From MAILER-DAEMON Tue Jun 23 19:23:40 2009 Date: 23 Jun 2009 19:23:40 -0300 From: Mail System Internal Data Subject: DON'T DELETE THIS MESSAGE -- FOLDER INTERNAL DATA Message-ID: <1245795820@mta.ca> X-IMAP: 1241481498 0000000094 Status: RO This text is part of the internal format of your mail folder, and is not a real message. It is created automatically by the mail system software. If deleted, important folder data will be lost, and it will be re-created with the data reset to initial values. From rrosebru@mta.ca Mon May 4 20:57:23 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 04 May 2009 20:57:23 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M17zT-0001lr-Ul for categories-list@mta.ca; Mon, 04 May 2009 20:54:32 -0300 Mime-Version: 1.0 (Apple Message framework v752.2) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Content-Transfer-Encoding: 7bit From: Marco Grandis Subject: categories: Preprint: Limits in symmetric cubical categories Date: Mon, 4 May 2009 14:46:23 +0200 To: categories@mta.ca Sender: categories@mta.ca Precedence: bulk Reply-To: Marco Grandis Message-Id: Status: O X-Status: X-Keywords: X-UID: 1 The following preprint is available; Limits in symmetric cubical categories (On weak cubical categories, II) Dip. Mat. Univ. Genova, Preprint 568 (2009). (25 pages) http://www.dima.unige.it/~grandis/CCat2.pdf (ps) Abstract. Weak symmetric cubical categories are equipped with an action of the n-dimensional symmetric group on the n-dimensional component; this action, besides simplifying the coherence conditions, yields a *symmetric* monoidal closed structure and one path functor. As a consequence, we have a clear notion of higher cubical transformations of symmetric cubical functors (which is not the case in the non-symmetric setting). Here we deal with symmetric cubical limits, showing that they can be constructed from symmetric cubical products, equalisers and tabulators. Weak double categories are a cubical truncation of the present structures; double limits are compared with the cubical ones. With best wishes Marco Grandis From rrosebru@mta.ca Wed May 6 21:07:50 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 06 May 2009 21:07:50 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M1r6X-00049d-AG for categories-list@mta.ca; Wed, 06 May 2009 21:04:49 -0300 Date: Wed, 6 May 2009 22:33:04 +0200 (CEST) From: Johannes Huebschmann To: categories@mta.ca Subject: categories: Lie algebras and failure of PBW MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Johannes Huebschmann Message-Id: Status: O X-Status: X-Keywords: X-UID: 2 Dear Friends and Colleagues On p. 331 of Magnus-Karras-Solitar, Combinatorial group theory there is a hint at an unpublished manuscript of R. Lyndon [1955] containing an example of a Lie algebra over an integral domain for which the statement of the PBW theorem is not true. I did not find this example in the literature not did I find any other hint at it. Does anybody know anything about it? Many thanks in advance Johannes From rrosebru@mta.ca Wed May 6 21:07:50 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 06 May 2009 21:07:50 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M1r7y-0004Fq-3c for categories-list@mta.ca; Wed, 06 May 2009 21:06:18 -0300 Date: Wed, 6 May 2009 23:42:48 +0200 (CEST) From: Peter Schuster To: Categories Subject: categories: MALOA network in Mathematical Logic: 18 PhD student positions (Leeds, Manchester, Oxford, Lyon, Paris, Muenster, Muenchen, Prague) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Peter Schuster Message-Id: Status: O X-Status: X-Keywords: X-UID: 3 18 PhD Positions in Mathematical Logic (MALOA Network) The Marie Curie (FP7) Initial Training Network in Mathematical Logic (MALOA) is a network with 8 Full Partners (Leeds (coordinator), Manchester, Oxford, Lyon (Lyon 1 and Lyon ENS), Paris (UPD), Muenster, Munich, Prague) and 3 Associated Partners (UEA, BT, Onera). Contract negotiations are still not concluded, so funding is nor absolutely confirmed, but it is expected to start on 1 October 2009, and run for 4 years. It will fund 18 PhD students and 20 short-term visitors (at least 3 months). All the full partners expect to make appointments for October 2009. For more information, seee http://www.logique.jussieu.fr/MALOA/ or contact Dugald Macpherson (the coordinator, h.d.macpherson@leeds.ac.uk) or the Scientist-in-Charge at the relevant partner. From rrosebru@mta.ca Fri May 8 12:21:08 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 08 May 2009 12:21:08 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M2RqO-00010t-OD for categories-list@mta.ca; Fri, 08 May 2009 12:18:36 -0300 Date: Wed, 6 May 2009 21:44:14 -0400 (EDT) From: Michael Barr To: Johannes Huebschmann , categories@mta.ca Subject: categories: Re: Lie algebras and failure of PBW MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Michael Barr Message-Id: Status: O X-Status: X-Keywords: X-UID: 4 It is not entirely clear what the PBW theorem is supposed to say over an arbitrary ring. Cartan-Eilenberg prove that if g is a K-free Lie algebra (K is an arbitrary ring with 1), then the enveloping algebra is K-free and on the same sort of basis as when K is a field (assume the basis is ordered, then you can take the set of increasing sequences as the basis of g^e). Although they don't, it is simple to show that if g is K-projective, so is g^e, although the idea of a basis is no longer meaningful. If g is an arbitrary K-Lie algebra, then I have no idea what a PBW theorem could say. Michael On Wed, 6 May 2009, Johannes Huebschmann wrote: > Dear Friends and Colleagues > > On p. 331 of > > Magnus-Karras-Solitar, Combinatorial group theory > > there is a hint at an unpublished > manuscript of R. Lyndon [1955] containing an example of a Lie > algebra over an integral domain > for which the statement of the PBW theorem is not true. > I did not find this example in the literature > not did I find any other hint at it. > Does anybody know anything about it? > > > > Many thanks in advance > > Johannes > > > > > From rrosebru@mta.ca Fri May 8 12:23:17 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 08 May 2009 12:23:17 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M2Ruq-0001Lc-Pz for categories-list@mta.ca; Fri, 08 May 2009 12:23:12 -0300 Date: Thu, 7 May 2009 22:39:37 +0200 (CEST) From: Johannes Huebschmann X-X-Sender: huebschm@cyprus.labomath.univ-lille1.fr, categories@mta.ca Subject: categories: Re: Lie algebras and failure of PBW MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Johannes Huebschmann Message-Id: Status: O X-Status: X-Keywords: X-UID: 5 Dear Michael Thank you for your message. My message was perhaps a bit cryptic. By statement of the PBW theorem I mean that, essentially, relative to the PBW filtration of the universal algebra UL of the Lie algebra L, the canonical algebra morphism from the symmetric algebra SL to the associated graded object E^0(UL) is an isomorphism. This then implies that the canonical map from L to UL is injective. More precisely: The universal algebra UL and the symmetric algebra SL both acquire filtered cocommutative coalgebra structures, and the canonical morphism SL --> E^0(UL) is one of Hopf algebras. One way to make precise the statement of the PBW theorem is to require the existence of an isomorphism UL --> SL of filtered coalgebras such that the associated graded morphism E^0(UL) --> SL is the inverse to the canonical morphism SL --> E^0(UL). Certainly the freeness of the Lie algebra is enough to guarantee the statement of the PBW theorem. More generally, L projective as a module over the ground ring still suffices I guess. Indeed, the arguments you give in Subsection 5.3 of your 1996 JPAA algebra paper imply this. Best regards Johannes On Wed, 6 May 2009, Michael Barr wrote: > It is not entirely clear what the PBW theorem is supposed to say over an > arbitrary ring. Cartan-Eilenberg prove that if g is a K-free Lie algebra (K > is an arbitrary ring with 1), then the enveloping algebra is K-free and on > the same sort of basis as when K is a field (assume the basis is ordered, > then you can take the set of increasing sequences as the basis of g^e). > Although they don't, it is simple to show that if g is K-projective, so is > g^e, although the idea of a basis is no longer meaningful. If g is an > arbitrary K-Lie algebra, then I have no idea what a PBW theorem could say. > > Michael > > On Wed, 6 May 2009, Johannes Huebschmann wrote: > >> Dear Friends and Colleagues >> >> On p. 331 of >> >> Magnus-Karras-Solitar, Combinatorial group theory >> >> there is a hint at an unpublished >> manuscript of R. Lyndon [1955] containing an example of a Lie >> algebra over an integral domain >> for which the statement of the PBW theorem is not true. >> I did not find this example in the literature >> not did I find any other hint at it. >> Does anybody know anything about it? >> >> >> >> Many thanks in advance >> >> Johannes >> >> >> >> >> > From rrosebru@mta.ca Sat May 9 10:36:41 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sat, 09 May 2009 10:36:41 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M2mgx-00042j-9H for categories-list@mta.ca; Sat, 09 May 2009 10:34:15 -0300 From: "David Espinosa" To: "Categories" Subject: categories: Axioms of elementary probability Date: Fri, 8 May 2009 23:02:04 -0700 MIME-Version: 1.0 Content-Type: text/plain;format=flowed; charset="iso-8859-1";reply-type=original Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: "David Espinosa" Message-Id: Status: O X-Status: X-Keywords: X-UID: 6 Here's a question about elementary (naive, finitist) probability. The proper, self-dual axioms for elementary probability are presumably P(0) = 0 P(X) = 1 P(A u B) + P(A n B) = P(A) + P(B) P's domain is a boolean algebra. P's codomain is [0,1]. What kind of algebraic structure is [0,1] in this case? What can we prove from this theory? The best I can think of is inclusion / exclusion: P(A u B u C) = P(A) + P(B) + P(C) - P(A n B) - P(A n C) - P(B n C) + P(A n B n C) P(A n B n C) = P(A) + P(B) + P(C) - P(A u B) - P(A u C) - P(B u C) + P(A u B u C) Thanks, David From rrosebru@mta.ca Tue May 12 09:28:00 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 12 May 2009 09:28:00 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M3r4j-00020J-TM for categories-list@mta.ca; Tue, 12 May 2009 09:27:13 -0300 Mime-Version: 1.0 (Apple Message framework v753.1) Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed Content-Transfer-Encoding: 7bit From: Ross Street Subject: categories: Re: Axioms of elementary probability Date: Tue, 12 May 2009 11:53:13 +1000 To: "David Espinosa" , "Categories" Sender: categories@mta.ca Precedence: bulk Reply-To: Ross Street Message-Id: Status: O X-Status: X-Keywords: X-UID: 7 A couple of years ago, Voevodsky gave an interesting talk at the Australian Math Soc Annual Meeting (at RMIT. Melbourne) about a categorical approach to probability theory. Google told me about: http://www.math.miami.edu/anno/voevodsky.htm and http://golem.ph.utexas.edu/category/2007/02/ category_theoretic_probability_1.html Ross On 09/05/2009, at 4:02 PM, David Espinosa wrote: > Here's a question about elementary (naive, finitist) probability. > The proper, self-dual axioms for elementary probability are presumably > > P(0) = 0 > P(X) = 1 > P(A u B) + P(A n B) = P(A) + P(B) From rrosebru@mta.ca Tue May 12 09:28:00 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 12 May 2009 09:28:00 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M3r2N-0001qG-O2 for categories-list@mta.ca; Tue, 12 May 2009 09:24:47 -0300 From: "David Espinosa" To: "Categories" Subject: categories: Axioms for elementary probability Date: Wed, 6 May 2009 19:44:01 -0700 MIME-Version: 1.0 Content-Type: text/plain;format=flowed; charset="iso-8859-1";reply-type=response Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: "David Espinosa" Message-Id: Status: O X-Status: X-Keywords: X-UID: 8 Here's a question about elementary (naive, finitist) probability. The proper, self-dual axioms for elementary probability are presumably P(0) = 0 P(X) = 1 P(A u B) + P(A n B) = P(A) + P(B) P's domain is a boolean algebra. P's codomain is [0,1]. I'm wondering, what kind of algebraic structure is [0,1] in this case? BTW, from these axioms we can prove nice things like inclusion / exclusion: P(A u B u C) = P(A) + P(B) + P(C) - P(A n B) - P(A n C) - P(B n C) + P(A n B n C) P(A n B n C) = P(A) + P(B) + P(C) - P(A u B) - P(A u C) - P(B u C) + P(A u B u C) David From rrosebru@mta.ca Tue May 12 09:28:48 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 12 May 2009 09:28:48 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M3r6C-00028K-N6 for categories-list@mta.ca; Tue, 12 May 2009 09:28:44 -0300 Date: Fri, 08 May 2009 10:41:02 -0700 From: PETER EASTHOPE Subject: categories: Elementary concepts of map objects To: categories@mta.ca MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-language: en Content-transfer-encoding: 7bit Content-disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: PETER EASTHOPE Message-Id: Status: O X-Status: X-Keywords: X-UID: 9 In light of the recent discussion here about the "horizontal line notation", I've returned to the introduction to map objects in L. & S., _Conceptual Mathematics_. This statement is in the rectangle at the top of page 314. ( Script.ChangeFont Courier8 ) T e X ----> Y T x Y ----> Y induces ------------- T x X ----> Y Evaluation map e induces a "correspondence". Is this horizontal line an implication or an equivalence or a map or a bijection? "Induces" seems plausible but exactly what is meant? Thanks, ... Peter E. From rrosebru@mta.ca Tue May 12 09:30:21 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 12 May 2009 09:30:21 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M3r7d-0002Hv-Rl for categories-list@mta.ca; Tue, 12 May 2009 09:30:13 -0300 From: "Ronnie Brown" To: Subject: categories: Fw: Category bulletin: Higher dimensional algebroids and crossed complexes Date: Mon, 11 May 2009 22:27:12 +0100 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: "Ronnie Brown" Message-Id: Status: O X-Status: X-Keywords: X-UID: 10 I think there is further interest in this area and so I have made = available Ghafar Mosa's 1986 University of Wales PhD thesis with the = above title at www.bangor.ac.uk/r.brown/mosa-thesis.html in order to give further publicity to Ghafar's work.=20 Ronnie Brown From rrosebru@mta.ca Wed May 13 09:39:45 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 13 May 2009 09:39:45 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4Di4-0002f5-Bm for categories-list@mta.ca; Wed, 13 May 2009 09:37:20 -0300 Date: Tue, 12 May 2009 16:34:07 +0100 From: Steve Vickers MIME-Version: 1.0 To: David Espinosa , Subject: categories: Re: Axioms of elementary probability In-Reply-To: Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Steve Vickers Message-Id: Status: RO X-Status: X-Keywords: X-UID: 11 Dear David, On structure: Domain L (say) just needs to be distributive lattice - not Boolean algebra. The axiom P(top) = 1 looks an obvious dual to P(bottom) = 0, but there's a lot to be gained from considering P with codomain [0,infinity] and forgetting P(top) = 1. Maps P: L -> [0,infinity] satisfying P(0) = 0 and the third (modular) law are called valuations - I believe this dates back to Birkhoff's book on lattice theory. In the case where L is a frame (complete lattice, with binary meet distributing over all joins) and P is Scott continuous, P is called a continuous valuation. These have been studied in domain theory (Jones, Plotkin: probabilistic power domain) and general locales (including by Heckmann, by Coquand and Spitters and by myself). More generally, the domain of P can fruitfully be any commutative monoid M. There is a universal valuation L -> M(L) in this generalized sense, with M(L) got by adjoining finite monoid structure to L and forcing the two laws. Coquand and Spitter cite an interesting construction of M(L) by Horn and Tarski. Let L* be the set of finite lists over L, and define a preorder on L* by [x_i]_{1 in I} <= [y_j]_{j in J} if for every natural number k, \/{x_K | K subseteq I, |K| = k} <= \/{y_K' | K' subseteq J, |K'| = k} where x_K = /\{x_i | i in K} etc. Then M(L) is isomorphic to L*/(equ reln corresponding to <=). The relations holding in M(L) are what can be proved from the theory. You give a ternary inclusion-and-exclusion for P(A u B u C). If you bring all the negative terms from right to left, it will still hold in M(L), and can be generalized from ternary to n-ary. I think you will get the dual (for P(A n B n C)) by considering L^op. Another interesting relation, which can be used in proving the Horn-Tarski result, is this: Sigma_{i = 0}^{n-1} x_i = Sigma_{k = 1}^{m} \/{x_I | I subseteq {0, ..., n-1}, |I| = k} Regards, Steve Vickers. References: Jones & Plotkin: "A probabilistic powerdomain of evaluations", LICS'89. Horn & Tarski: "Measures in Boolean algebras", Trans. Amer. Math. Soc. 64 (1948) Heckmann: "Probabilistic powerdomain, information systems and locales", MFPS VIII, Springer LNCS 802 (1994) Vickers: "A localic theory of lower and upper integrals", Math. Logic Quarterly 54 (2008) Coquand & Spitters: "Integrals and valuations", Journal of Logic and Analysis 1:3 (2009 David Espinosa wrote: > > Here's a question about elementary (naive, finitist) probability. > The proper, self-dual axioms for elementary probability are presumably > > P(0) = 0 > P(X) = 1 > P(A u B) + P(A n B) = P(A) + P(B) > > P's domain is a boolean algebra. P's codomain is [0,1]. > What kind of algebraic structure is [0,1] in this case? > > What can we prove from this theory? The best I can think of is inclusion / > exclusion: > > P(A u B u C) = P(A) + P(B) + P(C) - P(A n B) - P(A n C) - P(B n C) + P(A n > B n C) > P(A n B n C) = P(A) + P(B) + P(C) - P(A u B) - P(A u C) - P(B u C) + P(A u > B u C) > > Thanks, > > David > > > > From rrosebru@mta.ca Wed May 13 09:39:45 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 13 May 2009 09:39:45 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4Djl-0002oa-56 for categories-list@mta.ca; Wed, 13 May 2009 09:39:05 -0300 Date: Tue, 12 May 2009 10:52:13 -0700 (PDT) From: Jeff Egger Subject: categories: RE: Axioms of elementary probability To: Categories , Ross Street , David Espinosa MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Jeff Egger Message-Id: Status: O X-Status: X-Keywords: X-UID: 12 When I took a graduate course in probability, my lecturer began with =0Aa r= ather fine speech about the relationship between probability and =0A(finite= ) measure theory; in it, he discouraged identifying the two. =0AHis point = was that, insofar as probabilistic phenomena occur in the =0Areal world, no= mathematical theory can aspire to do more than model =0Aprobability---and = that, while (finite) measure theory has been very =0Asuccessful at modellin= g probability, it also has shortcomings.=0A=0AIntrigued, I sought him out l= ater for more thoughts on the subject.=0AIn the ensuing conversation, I gat= hered two tidbits of information=0Awhich readers of the list may appreciate= : that Gromov believes that =0Athe future of probability theory lies in bic= ategory theory; and that =0Adiscontent with measure theory stems, at least = in part, from its =0Afailure to adequately handle conditional probabilities= . =0A=0ATo be honest, the latter point heartened me even more than the fir= st.=0AFrom a purely aesthetic point of view, it has always irked me that on= e =0Acan meaningfully assign probabilities to things which are not events;= =0AI interpret this as meaning that the (standard) notion of event is too = =0Anarrow. Of course, it is also the case that the (standard) formula =0Af= or a conditional probability may result in the indeterminate 0/0, so =0Ait = would seem that [0,1] is also too small a codomain for the map =0A"probabil= ity", even classically understood (i.e., not getting into the=0A"free proba= bility" of Voiculescu). =0A=0ACheers,=0AJeff.=0A=0A----- Original Message -= ---=0A> From: Ross Street =0A> To: David Espinosa ; Categories =0A> Sent: Tuesday, M= ay 12, 2009 2:53:13 AM=0A> Subject: Re: categories: Axioms of elementary pr= obability=0A> =0A> A couple of years ago, Voevodsky gave an interesting tal= k at the=0A> Australian Math Soc=0A> Annual Meeting (at RMIT. Melbourne) ab= out a categorical approach to=0A> probability theory.=0A> Google told me ab= out:=0A> =0A> http://www.math.miami.edu/anno/voevodsky.htm=0A> and=0A> = http://golem.ph.utexas.edu/category/2007/02/=0A> category_theoretic_proba= bility_1.html=0A> =0A> Ross=0A> =0A> On 09/05/2009, at 4:02 PM, David Espin= osa wrote:=0A> =0A> > Here's a question about elementary (naive, finitist) = probability.=0A> > The proper, self-dual axioms for elementary probability = are presumably=0A> >=0A> > P(0) =3D 0=0A> > P(X) =3D 1=0A> > P(A u B) + = P(A n B) =3D P(A) + P(B)=0A=0A=0A From rrosebru@mta.ca Wed May 13 09:39:55 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 13 May 2009 09:39:55 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4DkV-0002tF-Qy for categories-list@mta.ca; Wed, 13 May 2009 09:39:51 -0300 From: Hasse Riemann To: Category mailing list Subject: categories: Correspondence between TQFT and state sum models? Date: Tue, 12 May 2009 21:31:08 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Hasse Riemann Message-Id: Status: O X-Status: X-Keywords: X-UID: 13 =20 Hi all categorists =20 Here are other questions i think about and need your help with. =20 2> Is there a correspondence in general between TQFTs and state sum models? If not what restrictions are necessary? =20 I think there is a correspondence but i am not sure. If it is=2C what is the correspondence then called? I am als interested in who discovered or proved it and in which year? =20 Also=2C do anyone have references about how to actually construct the corre= spondence both ways? Best regards Rafael Borowiecki From rrosebru@mta.ca Wed May 13 15:57:46 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 13 May 2009 15:57:46 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4Jd1-000550-1n for categories-list@mta.ca; Wed, 13 May 2009 15:56:31 -0300 From: Jean-Yves Marion To: Jean-Yves Marion Content-Type: text/plain; charset=ISO-8859-1; format=flowed; delsp=yes Content-Transfer-Encoding: quoted-printable Subject: categories: STACS 2010 Mime-Version: 1.0 (Apple Message framework v930.3) Date: Wed, 13 May 2009 15:19:00 +0200 X-PerlMx-Spam: Gauge=IIIIIII, Probability=8%, Report='FROM_SAME_AS_TO 0.05, BODY_SIZE_4000_4999 0, BODY_SIZE_5000_LESS 0, BODY_SIZE_7000_LESS 0, CELEB_NAMES 0, __CP_URI_IN_BODY 0, __CT 0, __CTE 0, __CT_TEXT_PLAIN 0, __FRAUD_419_SUBJ_ALLCAPS 0, __FROM_SAME_AS_TO2 0, __HAS_MSGID 0, __HAS_X_MAILER 0, __MIME_TEXT_ONLY 0, __MIME_VERSION 0, __MSGID_APPLEMAIL 0, __SANE_MSGID 0, __TO_MALFORMED_2 0' Sender: categories@mta.ca Precedence: bulk Reply-To: Jean-Yves Marion Message-Id: Status: O X-Status: X-Keywords: X-UID: 14 ************************************************************************ 27th International Symposium on Theoretical Aspects of Computer Science STACS 2010 - CALL FOR PAPERS MARCH 4-6, 2010, NANCY, FRANCE http://stacs.loria.fr/ ************************************************************************ SCOPE ******** Authors are invited to submit papers presenting original and unpublished research on theoretical aspects of computer science. Typical areas include (but are not limited to): * Algorithms and data structures, including: parallel and distributed =20= algorithms, computational geometry, cryptography, algorithmic learning theory; * Automata and formal languages; * Computational and structural complexity; * Logic in computer science, including: semantics, specification, and verification of programs, rewriting and deduction; * Current challenges, for example: biological computing, quantum computing, mobile and net computing. INVITED SPEAKERS *********************** Mikolaj Bojanczyk, Warsaw University Rolf Niedermeier, University of Jena Jacques Stern, Ecole Normale Sup=E9rieure PROGRAM COMMITTEE *************************** Markus Bl=E4ser, Saarland University Harry Buhrman, CWI, University of Amsterdam Thomas Colcombet, CNRS, Paris 7 University Anuj Dawar, University of Cambridge Arnaud Durand, Paris 7 University S=E1ndor Fekete, Braunschweig University of Technology Ralf Klasing, CNRS, Bordeaux University Christian Knauer, Freie Universit=E4t of Berlin Piotr Krysta, University of Liverpool Sylvain Lombardy, Marne la Vall=E9e University Parthasarathy Madhusudan, University of Illinois Jean-Yves Marion, Nancy University (co-chair) Pierre McKenzie, Universit=E9 de Montr=E9al Rasmus Pagh, IT University of Copenhagen Boaz Patt-Shamir, Tel Aviv University Christophe Paul, CNRS, Montpellier University Georg Schnitger, Frankfurt University Thomas Schwentick, TU Dortmund University (co-chair) Helmut Seidl, TU Munich Jir=ED Sgall, Charles University Sebastiano Vigna, Universit=E0 degli Studi di Milano Paul Vitanyi, CWI, Amsterdam SUBMISSIONS ******************* Authors are invited to submit a draft of a full paper with at most 12 pages (STACS style or similar - e.g. LaTeX article style, 11pt a4paper). The title page must contain a classification of the topic covered, preferably using the list of topics above. The paper should contain a succinct statement of the issues and of their motivation, a summary of the main results, and a brief explanation of their significance, accessible to non-specialist readers. Proofs omitted due to space constraints must be put into an appendix to be read by the program committee members at their discretion. Submissions deviating from these guidelines risk rejection. Electronic submissions should be formatted in PostScript or PDF.Simultaneous submission to other conferences with published proceedings is not allowed. PROCEEDINGS ******************** Accepted papers will appear in the proceedings of the Symposium, which =20= are published electronically in the LIPIcs (Leibniz International Proceedings in Informatics) series, available =20 through Dagstuhl's website. The LIPIcs series provides an ISBN for the proceedings volume and =20 manages the indexing issues. Accepted papers will also be archived in the open access electronic =20 repositories HAL and arXiv. These gateways, as well as the LIPIcs series, guarantee perennial, =20 free and easy electronic access, while the authors will retain the rights over their work. With their submission, authors consent to sign a license authorizing =20 the program committee chairs to organize the electronic publication of their paper if it is accepted. Further details are available on www.stacs-conf.org and on the =20 conference website. Participants of the conference will receive a printed version of the =20 proceedings. It is also planned to publish in a journal a selection of papers. IMPORTANT DATES *************************** Deadline for submission: September 22, 2009 Notification to authors: November 26, 2009 Final version: December 18, 2009 Symposium: March 4-6, 2010= From rrosebru@mta.ca Wed May 13 15:57:47 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 13 May 2009 15:57:47 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4Jdo-0005Dn-3O for categories-list@mta.ca; Wed, 13 May 2009 15:57:20 -0300 Date: Wed, 13 May 2009 15:52:41 +0200 To: Categories Subject: categories: Re: Axioms of elementary probability From: RFC Walters Content-Type: text/plain; format=flowed; delsp=yes; charset=utf-8 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: RFC Walters Message-Id: Status: O X-Status: X-Keywords: X-UID: 15 Readers of the list may be interested in the following paper: L. de Francesco Albasini, N. Sabadini, R.F.C. Walters, The compositional construction of Markov processes, arXiv:0901.2434v1, 2009. We believe that the identification of probability theory with measure theory should be replaced with a theory based on processes. To do this the theory of processes needs to be developed categorically. I have some comments on my web page about such a development. RFC Walters -- Using Opera's revolutionary e-mail client: http://www.opera.com/mail/ From rrosebru@mta.ca Wed May 13 15:58:24 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 13 May 2009 15:58:24 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4Jem-0005KO-Sm for categories-list@mta.ca; Wed, 13 May 2009 15:58:20 -0300 MIME-Version: 1.0 Date: Wed, 13 May 2009 08:49:48 -0700 Subject: categories: Re: Correspondence between TQFT and state sum models? From: John Baez To: categories@mta.ca Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: John Baez Message-Id: Status: O X-Status: X-Keywords: X-UID: 16 Rafael Borowiecki writes: Is there a correspondence in general between TQFTs and state sum models? There should be a correspondence between *extended* TQFTs and state sum models. The theory of extended TQFTs is only beginning to be developed, so this expected correspondence has not yet been proved. I recommend taking a look at this paper: Jacob Lurie On the Classification of Topological Field Theories http://arxiv.org/abs/0905.0465 Best, jb From rrosebru@mta.ca Thu May 14 08:38:15 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 14 May 2009 08:38:15 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4ZF1-0005S3-HQ for categories-list@mta.ca; Thu, 14 May 2009 08:36:47 -0300 MIME-Version: 1.0 Date: Wed, 13 May 2009 21:53:23 +0200 Subject: categories: Re: Correspondence between TQFT and state sum models? From: Urs Schreiber To: John Baez , categories@mta.ca Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Urs Schreiber Message-Id: Status: O X-Status: X-Keywords: X-UID: 17 This may depend on what exactly one understands under "state sum models". The Fukuma-Hosono-Kawai construction of 2d TQFTs from semisimple algebras has tradionally been called a state sum model description. Lauda and Pfeiffer have described it at great length in Lauda-Pfeiffer State sum construction of two-dimensional open-closed Topological Quantum Field Theories http://arxiv.org/abs/math.QA/0602047 When one internalizes these constructions from Vect into a modular tensor category, one obtains the state-sum-like construction of 2d CFT by Fuchs-Runkel-Schweigert, a review of which is for instance here I. Runkel, J. Fjelstad, J. Fuchs, Ch. Schweigert Topological and conformal field theory as Frobenius algebras math.CT/0512076. The Turaev-Viro model for 3d TQFT is also frequently called state sum model. I don't find the good review of Turaev-Viro that I wanted to link to right this moment, but googling shows up lots or useful links, it seems. Best, Urs On 5/13/09, John Baez wrote: > Rafael Borowiecki writes: > > Is there a correspondence in general between TQFTs and state sum models? > > > There should be a correspondence between *extended* TQFTs and state sum > models. > > The theory of extended TQFTs is only beginning to be developed, so this > expected correspondence has not yet been proved. I recommend taking a look > at this paper: > > Jacob Lurie > On the Classification of Topological Field Theories > http://arxiv.org/abs/0905.0465 > > Best, > > jb > > > From rrosebru@mta.ca Thu May 14 08:38:23 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 14 May 2009 08:38:23 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4ZGW-0005Yr-Gl for categories-list@mta.ca; Thu, 14 May 2009 08:38:20 -0300 MIME-Version: 1.0 Date: Wed, 13 May 2009 12:59:05 -0700 Subject: categories: Re: Axioms of elementary probability From: Greg Meredith To: Jeff Egger , Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Greg Meredith Message-Id: Status: O X-Status: X-Keywords: X-UID: 18 David, To my mind there are three presentations of a "theory" of probability. Two arrive at essentially the same theory by somewhat different means; these are frequentist and Bayesian presentations of "standard" probability theory. The third comes from a completely different direction: quantum mechanics. i remember when i first encountered the Dirac presentation of QM and the interpretation of as a probability amplitude. My first thought was -- hang on, doesn't that come with an obligation to prove that this aligns with (satisfies the axioms of) a theory of probability. In attempting to work that out for myself, i realized that it didn't; discovered a whole cottage industry of people who had made a similar observation; and argued to myself that of the various notions of probability put forward, this one enjoyed being rigourously employed in physical calculations verified to many decimal places. Best wishes, --greg On Tue, May 12, 2009 at 10:52 AM, Jeff Egger wrote: > > When I took a graduate course in probability, my lecturer began with > a rather fine speech about the relationship between probability and > (finite) measure theory; in it, he discouraged identifying the two. > His point was that, insofar as probabilistic phenomena occur in the > real world, no mathematical theory can aspire to do more than model > probability---and that, while (finite) measure theory has been very > successful at modelling probability, it also has shortcomings. > > Intrigued, I sought him out later for more thoughts on the subject. > In the ensuing conversation, I gathered two tidbits of information > which readers of the list may appreciate: that Gromov believes that > the future of probability theory lies in bicategory theory; and that > discontent with measure theory stems, at least in part, from its > failure to adequately handle conditional probabilities. > > To be honest, the latter point heartened me even more than the first. > From a purely aesthetic point of view, it has always irked me that one > can meaningfully assign probabilities to things which are not events; > I interpret this as meaning that the (standard) notion of event is too > narrow. Of course, it is also the case that the (standard) formula > for a conditional probability may result in the indeterminate 0/0, so > it would seem that [0,1] is also too small a codomain for the map > "probability", even classically understood (i.e., not getting into the > "free probability" of Voiculescu). > > Cheers, > Jeff. From rrosebru@mta.ca Thu May 14 08:39:18 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 14 May 2009 08:39:18 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4ZHP-0005cN-4R for categories-list@mta.ca; Thu, 14 May 2009 08:39:15 -0300 Date: Wed, 13 May 2009 17:26:36 -0700 (PDT) From: John MacDonald To: categories@mta.ca Subject: categories: FMCS 2009: Registration and Accommodation MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: John MacDonald Message-Id: Status: RO X-Status: X-Keywords: X-UID: 19 FMCS 2009 17th Workshop on Foundational Methods in Computer Science University of British Columbia, VANCOUVER, Canada MAY 28th - 31st, 2009 FOURTH ANNOUNCEMENT * * * Registration forms are available from the conference webpage http://www.pims.math.ca/scientific/general-event/foundational-methods-computer-science-2009 Accommodations may also be reserved from the same page. There are in fact some rooms still available. Reservations can be cancelled without penalty until 48 hours before the arrival date so it is to your advantage to book if there is even a slight possibility that you may attend. The next announcement will contain a complete list of participants so if you are not on the current list and you will or may attend, then please send email to johnm@math.ubc.ca with subject heading FMCS09 - WILL ATTEND or FMCS09 - MAY ATTEND. A schedule of talks will be posted on the website on or about May 20. In the meantime those who have never attended an FMCS meeting may wish to get an idea of the range of topics by looking at the talks given in 2008 at Halifax appearing in http://www.mscs.dal.ca/~selinger/fmcs2008/ The conference begins with a reception at 6pm on Thursday May 28th in the Ruth Blair room at Gage Towers on the University of British Columbia campus and ends at 1pm on Sunday May 31st. On May 29th there will be tutorials given by Ernie Manes(University of Massachusetts), Vaughan Pratt(Stanford University) and Pieter Hofstra(University of Ottawa). This will be followed by a day and a half of research talks by some of the participants listed below. There is still room for more participants and for a few more talks so if you would like to speak please let me know by May 18th before the program is posted. Current List of Participants: Robin Cockett, Computer Science University of Calgary Calgary, Alberta Brett Giles, Computer Science University of Calgary Calgary, Alberta Pieter Hofstra, Mathematics University of Ottawa Ottawa, Ontario Aaron Hunter, Computer Science Simon Fraser University Burnaby, British Columbia Mike Johnson, Mathematics and Computer Science Macquarie University Sydney, Australia John MacDonald, Mathematics University of British Columbia Vancouver, British Columbia Ernie Manes, Mathematics University of Massachusetts Amherst, Massachusetts Phil Mulry, Computer Science Colgate University Hamilton, New York Sean Nichols, Computer Science University of Calgary Calgary, Alberta Vaughan Pratt, Computer Science Stanford University Palo Alto, California Dorette Pronk, Mathematics Dalhousie University Halifax, Nova Scotia Brian Redmond, Computer Science University of Calgary Calgary, Alberta Bob Rosebrugh, Mathematics and Computer Science Mount Allison University Sackville, New Brunswick Mehrnoosh Sadrzadeh, Computer Science Oxford University Computing Laboratory Oxford, England R A G Seely, Mathematics McGill University Montreal, Quebec Shusaku Tsumoto, Computer Science and Medical Informatics Shimane University Izumo-city, Japan Art Stone, Mathematics Vancouver, British Columbia Hofstra student, Ottawa, Ontario The following paragraphs repeat the information from the first announcement. The Department of Mathematics at the University of British Columbia in cooperation with the Pacific Institute of Mathematical Sciences is hosting the Foundational Methods in Computer Science workshop on May 28th - 31st, 2009, on the University of British Columbia Campus in Vancouver, Canada The workshop is an annual informal meeting intended to bring together researchers in mathematics and computer science. There is a focus on the application of category theory in computer science. However, all those who are interested in category theory or computer science are welcome to attend. The meeting begins with a reception at 6pm in the Ruth Blair room in Walter Gage Towers on the UBC campus on Thursday May 28, 2009. The scientific program starts on May 29, and consists of a day of tutorials aimed at students and newcomers to category theory, as well as a day and a half of research talks. The meeting ends at mid-day on May 31. Research talks There will be some invited presentations, but the majority of the talks are solicited from the participants. If you wish to give a talk please send a title and abstract to johnm@math.ubc.ca. Time slots are limited, so please register early if you would like to be considered for a talk. Graduate student participation is particularly encouraged at FMCS. Previous meetings Previous FMCS meetings were held in Pullman (1992), Portland (1993), Vancouver (1994), Kananaskis (1995), Pullman (1996), Portland (1998), Kananaskis (1999), Vancouver (2000), Spokane (2001), Hamilton (2002), Ottawa (2003), Kananaskis (2004), Vancouver (2005), Kananaskis (2006), Hamilton (2007), and Halifax (2008). Organizing committee: Robin Cockett (Calgary) John MacDonald (UBC) Phil Mulry (Colgate) Peter Selinger (Dalhousie) Local Organizer: John MacDonald (UBC) From rrosebru@mta.ca Thu May 14 22:30:59 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 14 May 2009 22:30:59 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M4mD3-0005Mj-HH for categories-list@mta.ca; Thu, 14 May 2009 22:27:37 -0300 MIME-Version: 1.0 Date: Thu, 14 May 2009 15:13:16 -0500 Subject: categories: Variables From: Charles Wells To: catbb Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Charles Wells Message-Id: Status: O X-Status: X-Keywords: X-UID: 20 I just posted on variables here, with some mention of categorical thinking: http://sixwingedseraph.wordpress.com/2009/05/15/variables/ Charles Wells -- professional website: http://www.cwru.edu/artsci/math/wells/home.html blog: http://sixwingedseraph.wordpress.com/ abstract math website: http://www.abstractmath.org/MM//MMIntro.htm astounding math stories: http://www.abstractmath.org/MM//MMAstoundingMath.htm personal website: http://www.abstractmath.org/Personal/index.html From rrosebru@mta.ca Sun May 17 16:59:48 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 17 May 2009 16:59:48 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M5mTU-0002Yd-38 for categories-list@mta.ca; Sun, 17 May 2009 16:56:44 -0300 MIME-Version: 1.0 Date: Fri, 15 May 2009 01:24:25 +0200 Subject: categories: FLoC 2010: First Announcement From: Nicole Schweikardt To: floc2010@informatik.uni-frankfurt.de Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Nicole Schweikardt Message-Id: Status: RO X-Status: X-Keywords: X-UID: 21 2010 FEDERATED LOGIC CONFERENCE (FLoC'10) Edinburgh, Scotland, U.K. July 9-21, 2010 http://www.floc-conference.org * In 1996, as part of its Special Year on Logic and Algorithms, DIMACS hosted the first Federated Logic Conference (FLoC). It was modeled after the successful Federated Computer Research Conference (FCRC), and synergetically brought together conferences that apply logic to computer science. The second Federated Logic Conference (FLoC'99) was held in Trento, Italy, in 1999, the third (FLoC'02) was held in Copenhagen, Denmark, in 2002, and the fourth (FLoC'06) was held in Seattle, Washington, USA. * We are pleased to announce the fifth Federated Logic Conference (FLoC'10) to be held in Edinburgh, Scotland, U.K. (www.edinburgh.org), in July 2010, at the School of Informatics at University of Edinburgh (www.inf.ed.ac.uk). * The following conferences will participate in FLoC: Int'l Conference on Computer-Aided Verification (CAV) Int'l Conference on Logic Programming (ICLP) Int'l Joint Conference on Automated Reasoning (IJCAR) Int'l Conference on Interactive Theorem Proving (ITP) IEEE Symposium on Logic in Computer Science (LICS) Int'l Conference on Rewriting Techniques and Applications (RTA) Int'l Conference on Theory and Applications of Satisfiability Testing (SAT) * Pre-conference workshops will be held on July 9-10. ITP, LICS, RTA, and SAT will be held in parallel on July 11-14, to be followed by mid-conference workshops on July 14-15. CAV, ICLP, and IJCAR will be held in parallel on July 16-19, to be followed by post-conference workshops on July 20-21. Plenary events involving all the conferences are planned. There will be receptions in the Edinburgh Castle and at the National Galleries of Scotland. * The call for workshop proposals can be found at the FLoC web page (http://www.floc-conference.org). Calls for papers will be issued in the near future. For additional information regarding the participating meetings, please check the FLoC web page later this summer. * FLoC'10 Steering Committee: - General Chair: Moshe Y. Vardi - Conference Co-chairs: Leonid Libkin, Gordon Plotkin - CAV Representative: Edmund Clarke - ICLP Representative: Manuel Hermenegildo - IJCAR Representative: Alan Bundy - ITP Representative: Tobias Nipkow - LICS Representative: Martin Abadi - RTA Representative: Juergen Giesl - SAT Representative: Enrico Giunchiglia - EasyChair Representative: Andrei Voronkov ---------------------- You are subscribed to the FLoC 2010 mailing list. To unsubscribe please send an email to majordomo@informatik.uni-frankfurt.de with the keywords unsubscribe floc2010 in the message body. From rrosebru@mta.ca Sun May 17 17:01:04 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 17 May 2009 17:01:04 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M5mXb-0002ky-Hn for categories-list@mta.ca; Sun, 17 May 2009 17:00:59 -0300 MIME-Version: 1.0 Date: Fri, 15 May 2009 08:43:14 -0500 Message-ID: <20a4d2bd0905150643p40ffe794u378e494686841574@mail.gmail.com> Subject: categories: Retry on variables From: Charles Wells To: catbb Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Charles Wells Status: RO X-Status: X-Keywords: X-UID: 22 [Note from moderator: Third time lucky, I hope. For many of you this message showed as an attachment, or not at all, when sent twice before. If it fails this time I'll send the substance from my own account. Apologies if you are seeing the message for the third time... ] When this message arrived in my mailbox it was missing the explanation. The following post on my blog may be of interest to readers of catbb. http://sixwingedseraph.wordpress.com/2009/05/15/variables/ Charles Wells -- professional website: http://www.cwru.edu/artsci/math/wells/home.html blog: http://sixwingedseraph.wordpress.com/ abstract math website: http://www.abstractmath.org/MM//MMIntro.htm astounding math stories: http://www.abstractmath.org/MM//MMAstoundingMath.htm personal website: http://www.abstractmath.org/Personal/index.html From rrosebru@mta.ca Sun May 17 17:03:25 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 17 May 2009 17:03:25 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M5mZb-0002sz-Sv for categories-list@mta.ca; Sun, 17 May 2009 17:03:04 -0300 MIME-Version: 1.0 Date: Fri, 15 May 2009 12:35:43 -0700 Message-ID: <5de3f5ca0905151235l29a483c4sa7184bd4e06073ad@mail.gmail.com> Subject: categories: Re: Axioms of elementary probability From: Greg Meredith To: Jeff Egger , Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Greg Meredith Status: RO X-Status: X-Keywords: X-UID: 23 David, Here 's an arXiv reference for the "cottage industry" i was referring to. Best wishes, --greg On Wed, May 13, 2009 at 12:59 PM, Greg Meredith < lgreg.meredith@biosimilarity.com> wrote: > David, > > To my mind there are three presentations of a "theory" of probability. Two > arrive at essentially the same theory by somewhat different means; these are > frequentist and Bayesian presentations of "standard" probability theory. The > third comes from a completely different direction: quantum mechanics. i > remember when i first encountered the Dirac presentation of QM and the > interpretation of as a probability amplitude. My first thought was > -- hang on, doesn't that come with an obligation to prove that this aligns > with (satisfies the axioms of) a theory of probability. In attempting to > work that out for myself, i realized that it didn't; discovered a whole > cottage industry of people who had made a similar observation; and argued to > myself that of the various notions of probability put forward, this one > enjoyed being rigourously employed in physical calculations verified to many > decimal places. > > Best wishes, > From rrosebru@mta.ca Sun May 17 17:03:57 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 17 May 2009 17:03:57 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M5maF-0002v1-Rl for categories-list@mta.ca; Sun, 17 May 2009 17:03:43 -0300 From: "A. MANI" To: "Categories" Subject: categories: Re: Axioms for elementary probability Date: Sat, 16 May 2009 04:19:34 +0530 MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: "A. MANI" Message-Id: Status: RO X-Status: X-Keywords: X-UID: 24 On Thursday 07 May 2009 08:14:01 David Espinosa wrote: > Here's a question about elementary (naive, finitist) probability. > The proper, self-dual axioms for elementary probability are presumably > > P(0) = 0 > P(X) = 1 > P(A u B) + P(A n B) = P(A) + P(B) > > P's domain is a boolean algebra. P's codomain is [0,1]. > I'm wondering, what kind of algebraic structure is [0,1] in this case? It is a partial algebra with partial operations \wedge, v, +, o, 0, 1 (the order can be written with \wedge, v) a+b is defined iff a+b =< 1 in R a o b is always defined (multiplication) plenty of strong weak equalities hold. What is the generalization to categories? Best A. Mani -- A. Mani CLC, ASL, AMS, CMS http://amani.topcities.com From rrosebru@mta.ca Sun May 17 17:04:33 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 17 May 2009 17:04:33 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M5mam-0002x6-DP for categories-list@mta.ca; Sun, 17 May 2009 17:04:16 -0300 Date: Sun, 17 May 2009 14:35:01 -0400 (EDT) From: Robert Seely To: Categories List Subject: categories: MakkaiFest, 18 - 20 June (Montreal) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Robert Seely Message-Id: Status: RO X-Status: X-Keywords: X-UID: 25 A reminder, a request, and an invitation: Information about the following meeting may be found on the webpage: http://www.crm.umontreal.ca/Makkaifest09/ Models, Logics and Higher-Dimensional Categories A tribute to the work of Mihaly Makkai 18 - 20 June 2009 at Centre de Recherche Math\'ematique (CRM) in Montreal with a 1-day workshop at McGill on 18 June. ----------------- If you wish to stay near the CRM for the MakkaiFest, there are two accommodation options, as given on the meeting webpage. http://www.crm.umontreal.ca/Makkaifest09/logement_e.php - First, a *very* small number of rooms are still available at the Terrasse Royale Hotel at the meeting rate of $CAN 125 per night. If you want one of these rooms you should contact Louis Pelletier immediately (do NOT contact the hotel directly if you want the conference rate). Once the reserved rooms are all taken, we cannot guarantee there will still be rooms available at the Terrasse Royale. - The University residence has simple rooms available for very reasonable rates. Check their website - you should make reservations with them directly. http://www.studioshotel.ca/index.php?lang=en&d=h ------ If you are interested in speaking in the 1-day Workshop on June 18th (at McGill), please let us know as soon as possible - there are VERY FEW places available in the program, and at this time we cannot guarantee all requests can be accommodated. ------ If you intend to attend the meeting banquet, please let one of us (Phil or Robert) know as soon as possible, so we can inform the restaurant of the numbers attending. We have to give them a final number early in June, and once that has been done, we cannot guarantee latecomers can be accommodated. We'd rather not have to disappoint participants. ------ Finally, we encourage you to register (on-line at the meeting webpage) as soon as possible. ---------------- Phil Scott Robert Seely -- From rrosebru@mta.ca Tue May 19 09:47:34 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 19 May 2009 09:47:34 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M6Oga-0000Nu-Dj for categories-list@mta.ca; Tue, 19 May 2009 09:44:48 -0300 To: categories@mta.ca Subject: categories: FICS'09 Call for papers - Fixed Points in Computer Science (CSL'09 workshop) Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Date: Mon, 18 May 2009 19:28:17 +0300 From: Tarmo Uustalu Sender: categories@mta.ca Precedence: bulk Reply-To: Tarmo Uustalu Message-Id: Status: O X-Status: X-Keywords: X-UID: 26 Call for Papers (Extended Abstracts) 6th Workshop on Fixed Points in Computer Science, FICS 2009 Coimbra, Portugal, 12-13 September 2009, a satellite workshop of CSL 2009, colocated with PPDP 2009, LOPSTR 2009 http://cs.ioc.ee/fics09/ Background Fixed points play a fundamental role in several areas of computer science and logic by justifying induction and recursive definitions. The construction and properties of fixed points have been investigated in many different frameworks such as: design and implementation of programming languages, program logics, databases. The aim of the workshop is to provide a forum for researchers to present their results to those members of the computer science and logic communities who study or apply the theory of fixed points. Previous workshops where held in Brno (1998, MFCS/CSL workshop), Paris (2000, LC workshop), Florence (2001, PLI workshop), Copenhagen (2002, LICS (FLoC) workshop), Warsaw (2003, ETAPS workshop). Topics include, but are not restricted to: * categorical, metric and ordered fixed point models * fixed points in algebra and coalgebra * fixed points in languages and automata * fixed points in programming language semantics * the mu-calculus and fixed points in modal logic * fixed points in process algebras and process calculi * fixed points in the lambda-calculus, = functional programming and type theory * fixed points in relation to dataflow and circuits * fixed points in logic programming and theorem proving * finite model theory, descriptive complexity theory, = fixed points in databases Invited speakers tba Contributed talks Selection of contributed talks is based on extended abstracts/short papers of 3..6 pp formatted with easychair.cls. Submission is via EasyChair by 30 June 2009. The authors will be notified of acceptance/rejection by 21 July 2009. Camera-ready versions of the accepted contributions, due by 11 August 2009, will be published for distribution at the workshop as a technical report. If the number and quality of submissions and accepted talks warrant this, EDP Sciences will publish a special issue of Theoretical Informatics and Applications. The special issues of the previous editions of FICS appeared in the same journal. Programme committee Yves Bertot (INRIA Sophia Antipolis) Anuj Dawar (University of Cambridge) Peter Dybjer (Chalmers University of Technology) Zolt=E1n =C9sik (University of Szeged) Masahito Hasegawa (Kyoto University) Anna Ing=F3lfsd=F3ttir (Reykjavik University) Ralph Matthes (IRIT, Toulouse) (co-chair) Jan Rutten (CWI and Vrije Universiteit Amsterdam) Luigi Santocanale (LIF, Marseille) Alex Simpson (University of Edinburgh) Tarmo Uustalu (Institute of Cybernetics, Tallinn) (co-chair) Igor Walukiewicz (LaBRI, Bordeaux) Sponsors EXCS, Estonian Centre of Excellence in Computer Science From rrosebru@mta.ca Tue May 19 16:11:53 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 19 May 2009 16:11:53 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M6Ui1-0006N4-8X for categories-list@mta.ca; Tue, 19 May 2009 16:10:41 -0300 MIME-Version: 1.0 Date: Tue, 19 May 2009 01:27:58 -0500 Subject: categories: Lawvere papers From: "Vasili I. Galchin" To: Categories mailing list Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: "Vasili I. Galchin" Message-Id: Status: RO X-Status: X-Keywords: X-UID: 28 [Note from moderator: apologies to those who receive multiple copies; the error in forwarding this and a previous message has been rectified (thanks to Vaughan Pratt for identifying it).] Hello, I know that some Lawvere papers are available on TAC, but is there a list of all Lawvere papers online and if so, which URL? Kind regards, Vasili From rrosebru@mta.ca Wed May 20 10:53:14 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 20 May 2009 10:53:14 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M6mBQ-0001RS-Kp for categories-list@mta.ca; Wed, 20 May 2009 10:50:12 -0300 Date: Tue, 19 May 2009 17:50:47 -0400 (EDT) From: Robert Seely To: "Vasili I. Galchin" , Subject: categories: Re: Lawvere papers References: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Robert Seely Message-Id: Status: RO X-Status: X-Keywords: X-UID: 29 You might try his home page: http://www.acsu.buffalo.edu/~wlawvere/downloadlist.html -= rags =- On Tue, 19 May 2009, Vasili I. Galchin wrote: > [Note from moderator: apologies to those who receive multiple copies; the > error in forwarding this and a previous message has been rectified (thanks > to Vaughan Pratt for identifying it).] > > Hello, > > I know that some Lawvere papers are available on TAC, but is there a > list of all Lawvere papers online and if so, which URL? > > Kind regards, > > Vasili > > -- From rrosebru@mta.ca Wed May 20 10:53:14 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 20 May 2009 10:53:14 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M6mBv-0001Tr-GR for categories-list@mta.ca; Wed, 20 May 2009 10:50:43 -0300 MIME-Version: 1.0 From: Alex Hoffnung Date: Tue, 19 May 2009 22:10:51 -0500 Subject: categories: Enrichment over a monoidal bicategory To: categories@mta.ca Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Alex Hoffnung Message-Id: Status: O X-Status: X-Keywords: X-UID: 30 Hi I have found that there is a fairly straightforward way to generalize the notion of enrichment over a monoidal category to enrichment over a monoidal bicategory. Namely, a "bicategory enriched over a monoidal bicategory V" consists of the following: 1) a collection of "objects" A, B, C,... 2) for any pair of objects A,B, an object in V called hom(A,B) 3) for any triple of objects A,B,C a morphism in V called composition: hom(A,B) tensor hom(B,C) -> hom(A,C) where "tensor" is the tensor product in V. 4) for any object A a morphism in V called identity: I_A -> hom(A,A) 5) for any quadruple of objects A,B,C,D a 2-isomorphism in V called the associator, which does the obvious thing. plus left and right unitors, and so on with all the axioms closely following those of the definition of a bicategory. I am looking to be pointed in the right direction in the literature. Can anyone help? I am aware of the fc-multicategories by Leinster and earlier work by Walters, but those do not seem to use the monoidal structure to enrich as I want. Best, Alex Hoffnung From rrosebru@mta.ca Wed May 20 10:57:47 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 20 May 2009 10:57:47 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M6mIc-00024s-9U for categories-list@mta.ca; Wed, 20 May 2009 10:57:38 -0300 MIME-Version: 1.0 Date: Tue, 19 May 2009 18:04:56 -0500 Subject: categories: Re: Lawvere papers From: "Vasili I. Galchin" To: Robert Seely , Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: "Vasili I. Galchin" Message-Id: Status: O X-Status: X-Keywords: X-UID: 31 Hi Robert, I should have said that I am looking for one paper on "variable sets" and another on "adjoints", i.e. Lawvere adjoint revelation. I would like soft copy. Kind regards, Vasili On Tue, May 19, 2009 at 4:50 PM, Robert Seely wrote: > You might try his home page: > > http://www.acsu.buffalo.edu/~wlawvere/downloadlist.html > > -= rags =- > > From rrosebru@mta.ca Thu May 21 13:14:07 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:14:07 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7Atj-0003jM-4c for categories-list@mta.ca; Thu, 21 May 2009 13:13:35 -0300 Date: Wed, 20 May 2009 15:16:34 +0100 From: Steve Vickers MIME-Version: 1.0 To: Categories , constructivenews@googlegroups.com Subject: categories: Post-doc position at Birmingham: toposes and quantum theory Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Steve Vickers Message-Id: Status: O X-Status: X-Keywords: X-UID: 32 I recently announced a Research Fellowship at Birmingham. Its aim is to apply techniques of geometric logic to the topos approaches to quantum theory (Isham and Doering at Imperial, Landsman's group at Nijmegen). The job is now posted online at Birmingham, application deadline 10th June 2009. Go to http://www.hr.bham.ac.uk/jobs/ and search by post number 43408. There will be an advertisement on http://www.jobs.ac.uk/ in the next couple of days. You can also find all that information on my website at http://www.cs.bham.ac.uk/~sjv/geophysics.php The "more detailed project description" is at http://www.cs.bham.ac.uk/~sjv/geophysics/Summary.pdf Regards, Steve Vickers. From rrosebru@mta.ca Thu May 21 13:14:07 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:14:07 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7As2-0003Yg-Hz for categories-list@mta.ca; Thu, 21 May 2009 13:11:50 -0300 Date: Wed, 20 May 2009 15:12:08 +0100 (BST) From: Richard Garner To: Alex Hoffnung , categories@mta.ca Subject: categories: Re: Enrichment over a monoidal bicategory MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Richard Garner Message-Id: Status: O X-Status: X-Keywords: X-UID: 33 Dear Alex, A fair amount of the theory of enriched bicategories is worked out in Steve Lack's PhD thesis "The algebra of distributive and extensive categories". I don't think there have been any further attempts to develop the theory to any serious degree. Best wishes, Richard --On 19 May 2009 22:10 Alex Hoffnung wrote: > Hi > > I have found that there is a fairly straightforward way to generalize > the notion of enrichment over a monoidal category to enrichment over a > monoidal bicategory. Namely, a "bicategory enriched over a monoidal > bicategory V" consists of the following: > > 1) a collection of "objects" A, B, C,... > > 2) for any pair of objects A,B, an object in V called hom(A,B) > > 3) for any triple of objects A,B,C a morphism in V called composition: > hom(A,B) tensor hom(B,C) -> hom(A,C) > where "tensor" is the tensor product in V. > > 4) for any object A a morphism in V called identity: I_A -> hom(A,A) > > 5) for any quadruple of objects A,B,C,D a 2-isomorphism in V called > the associator, which does the obvious thing. > > plus left and right unitors, and so on with all the axioms closely > following those of the definition of a bicategory. > > I am looking to be pointed in the right direction in the literature. > Can anyone help? I am aware of the fc-multicategories by Leinster and > earlier work by Walters, but those do not seem to use the monoidal > structure to enrich as I want. > > Best, > Alex Hoffnung > > > From rrosebru@mta.ca Thu May 21 13:14:10 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:14:10 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7AuF-0003lw-Ks for categories-list@mta.ca; Thu, 21 May 2009 13:14:07 -0300 Date: Wed, 20 May 2009 16:19:34 +0200 From: Andree Ehresmann To: categories@mta.ca Subject: categories: Site internet de Andree C. Ehresmann MIME-Version: 1.0 Content-Type: text/plain;charset=ISO-8859-1;DelSp="Yes";format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Andree Ehresmann Message-Id: Status: O X-Status: X-Keywords: X-UID: 34 For those interested in old stuff, I mention the new internet site I have opened. It contains information on my 50 years research with postings of many of my publications and online references to others. It also contains the diapos of my Calais conference in 2008 on distructures and Schwartz distributions, as well as a long unpublished paper developing it. The address is http://pagesperso-orange.fr/ehres This site complements my joint site with Jean-Paul Vanbremeersch on our Memory Evolutive Systems http://pagesperso-orange.fr/vbm-ehr Kind regards Andree From rrosebru@mta.ca Thu May 21 13:14:46 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:14:46 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7Aup-0003pJ-0p for categories-list@mta.ca; Thu, 21 May 2009 13:14:43 -0300 Date: Wed, 20 May 2009 23:23:25 +0200 From: Andre.Rodin@ens.fr To: categories@mta.ca, charles@abstractmath.org Subject: categories: sketch theory MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Andre.Rodin@ens.fr Message-Id: Status: O X-Status: X-Keywords: X-UID: 35 Dear Charles and others: this http://www.cwru.edu/artsci/math/wells/pub/pdf/sketch.pdf is your very useful overview of Sketch theory dated back to 1993. I wonde= r how much it omits today: are there significant research programmes in this fi= eld emerged during last 15 years? What should I look at first of all? Many th= anks in advance. Andrei From rrosebru@mta.ca Thu May 21 13:15:22 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:15:22 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7AvP-0003tz-6Q for categories-list@mta.ca; Thu, 21 May 2009 13:15:19 -0300 MIME-Version: 1.0 Date: Wed, 20 May 2009 15:26:45 -0700 Subject: categories: Prof From: Mike Stay To: categories Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Mike Stay Message-Id: Status: O X-Status: X-Keywords: X-UID: 36 The bicategory of (small categories, profunctors, and natural transformations), should be equivalent to the 2-category of (presheaf categories, colimit-preserving functors, and natural transformations). Has someone proved this? If so, where? Thanks! -- Mike Stay - metaweta@gmail.com http://math.ucr.edu/~mike http://reperiendi.wordpress.com From rrosebru@mta.ca Thu May 21 13:16:36 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:16:36 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7AwY-00043R-UD for categories-list@mta.ca; Thu, 21 May 2009 13:16:31 -0300 From: Hasse Riemann To: Category mailing list Subject: categories: What is classified by cohomology? Date: Wed, 20 May 2009 23:09:28 +0000 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Hasse Riemann Message-Id: Status: O X-Status: X-Keywords: X-UID: 37 =20 Hi all categorists =20 Here is another questions i think about and need your help with. =20 3> What does the cohomology H^n(X=3Bcoefficients) classify=2C for X a more gen= eral object then a group and especially when X is a category? I know that the case X=3Dgroup gives n-torsors. And how come that the classification is independant of the coefficients? =20 Best regards Rafael Borowiecki From rrosebru@mta.ca Thu May 21 13:19:08 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:19:08 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7Ayw-0004Jw-Vh for categories-list@mta.ca; Thu, 21 May 2009 13:18:59 -0300 Date: Thu, 21 May 2009 13:52:41 +1000 Subject: categories: Re: Enrichment over a monoidal bicategory From: Steve Lack To: Alex Hoffnung , categories Mime-version: 1.0 Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Steve Lack Message-Id: Status: O X-Status: X-Keywords: X-UID: 38 Dear Alex, As you say, it is not hard to define bicategories enriched in a monoidal bicategory; in fact the only hard thing is saying what a monoidal bicategory is. As you also point out, these are quite different to categories enriched in a bicategory, in the sense of Walters. The latter are still "strict" structures; indeed they are categorical rather than 2-categorical, so there is no room for any non-strictness. Benabou [Introduction to bicategories, SLN 47] defined a polyad in a bicategory B to be a set X equipped with a morphism of bicategories X_ch-->B, where X_ch is the bicategory with object-set X and with all hom-categories terminal. This is exactly what Walters later called a B-enriched category, and used in his study of sheaves. (Benabou gave categories enriched in a monoidal category as an example of polyads, but did not explicitly suggest that polyads were a sort of enriched category.) Gordon, Power, and Street [Coherence for tricategories, AMS Memoirs] considered the next dimension up. For a tricategory T, they called a morphism of tricategories X_ch-->T a T-category, although did not go on to use this notion in any way. The case where T has one object is exactly the situation you discuss. There is a certain amount of flabbiness in this notion of T-categories, coming, for example, from the use of not necessarily normal homomorphisms. A tighter, more explicit definition of bicategories enriched in monoidal bicategories was given by Sean Carmody in his 1995 Cambridge thesis. They also appeared in my thesis the following year. More recently, there has been quite a lot of work done on the one-object case: pseudomonoids in Gray-monoids, or equivalently pseudomonads in Gray-categories. Hope this helps. Steve Lack. On 20/05/09 1:10 PM, "Alex Hoffnung" wrote: > Hi > > I have found that there is a fairly straightforward way to generalize > the notion of enrichment over a monoidal category to enrichment over a > monoidal bicategory. Namely, a "bicategory enriched over a monoidal > bicategory V" consists of the following: > > 1) a collection of "objects" A, B, C,... > > 2) for any pair of objects A,B, an object in V called hom(A,B) > > 3) for any triple of objects A,B,C a morphism in V called composition: > hom(A,B) tensor hom(B,C) -> hom(A,C) > where "tensor" is the tensor product in V. > > 4) for any object A a morphism in V called identity: I_A -> hom(A,A) > > 5) for any quadruple of objects A,B,C,D a 2-isomorphism in V called > the associator, which does the obvious thing. > > plus left and right unitors, and so on with all the axioms closely > following those of the definition of a bicategory. > > I am looking to be pointed in the right direction in the literature. > Can anyone help? I am aware of the fc-multicategories by Leinster and > earlier work by Walters, but those do not seem to use the monoidal > structure to enrich as I want. > > Best, > Alex Hoffnung > > From rrosebru@mta.ca Thu May 21 13:19:40 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 21 May 2009 13:19:40 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7AzY-0004Nx-PO for categories-list@mta.ca; Thu, 21 May 2009 13:19:36 -0300 Date: Thu, 21 May 2009 16:12:36 +0200 From: Jaap van Oosten MIME-Version: 1.0 To: Foundations of Mathematics , Categories Subject: categories: paper: Partial Combinatory Algebras of Functions Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Jaap van Oosten Message-Id: Status: O X-Status: X-Keywords: X-UID: 39 A new paper of mine is available on the Arxiv: http://front.math.ucdavis.edu/0905.2665 *Abstract:* We employ the notions of `sequential function' and `interrogation' (dialogue) in order to define new partial combinatory algebra structures on sets of functions. These structures are analyzed using J. Longley's preorder-enriched category of partial combinatory algebras and decidable applicative structures.We also investigate total combinatory algebras of partial functions. One of the results is, that every realizability topos is a quotient of a realizability topos on a total combinatory algebra. From rrosebru@mta.ca Fri May 22 10:08:19 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 22 May 2009 10:08:19 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7URk-0003iS-OY for categories-list@mta.ca; Fri, 22 May 2009 10:06:00 -0300 MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-1 Date: Thu, 21 May 2009 20:04:23 +0200 From: Fernando Muro To: Hasse Riemann , Subject: categories: Re: What is classified by cohomology? Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Fernando Muro Message-Id: Status: O X-Status: X-Keywords: X-UID: 40 Dear Hasse, > What does the cohomology H^n(X;coefficients) classify, for X a more gen= eral > object then a group and especially when X is a category? > I know that the case X=3Dgroup gives n-torsors. Group cohomology also classifies crossed extensions: Huebschmann, Johannes Crossed $n$-fold extensions of groups and cohomology. Comment. Math. Helv. 55 (1980), no. 2, 302--313.=20 There is a similar approach for cohomology of categories in: Baues, Hans-Joachim(D-MPI); Minian, Elias Gabriel(D-MPI) Track extensions of categories and cohomology. (English summary) $K$-Theory 23 (2001), no. 1, 1--13.=20 The cases n =3D 0, 1, 2, 3 were known before, see references therein. Best, Fernando --=20 Fernando Muro Universitat de Barcelona, Departament d'=C0lgebra i Geometria http://atlas.mat.ub.es/personals/muro/ From rrosebru@mta.ca Fri May 22 10:08:19 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 22 May 2009 10:08:19 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7USx-0003pW-Vj for categories-list@mta.ca; Fri, 22 May 2009 10:07:16 -0300 MIME-Version: 1.0 Date: Thu, 21 May 2009 12:43:12 -0700 Subject: categories: Re: sketch theory From: John Baez To: categories@mta.ca Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: John Baez Message-Id: Status: O X-Status: X-Keywords: X-UID: 41 Dear Categorists - Andrei Rodin pointed out this paper by Charles Wells: http://www.cwru.edu/artsci/math/wells/pub/pdf/sketch.pdf I took a look. In section 4.1 it mentions that people have given a finite limits sketch for cartesian closed categories. I'm curious about how this works, Unfortunately the list of references given here is quite long. Can anyone help me find a reference on a sketch for CCC's? Best, jb From rrosebru@mta.ca Fri May 22 10:08:24 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 22 May 2009 10:08:24 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7UTk-0003tz-FS for categories-list@mta.ca; Fri, 22 May 2009 10:08:04 -0300 Date: Thu, 21 May 2009 21:55:11 +0200 From: Thomas Hildebrandt MIME-Version: 1.0 To: Mike Stay , categories Subject: categories: Re: Prof Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Thomas Hildebrandt Message-Id: Status: RO X-Status: X-Keywords: X-UID: 42 Mike Stay wrote: > The bicategory of (small categories, profunctors, and natural > transformations), should be equivalent to the 2-category of (presheaf > categories, colimit-preserving functors, and natural transformations). > Has someone proved this? If so, where? > > Thanks! > Dear Mike, You may have a look at Prop. 4.2.4 in the PhD thesis of Gian Luca Cattani from BRICS, University of Aarhus, available at http://www.daimi.au.dk/~luca/thesis.html Best Thomas Hildebrandt IT University of Copenhagen www.itu.dk From rrosebru@mta.ca Fri May 22 10:10:39 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Fri, 22 May 2009 10:10:39 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M7UVb-00046N-Ug for categories-list@mta.ca; Fri, 22 May 2009 10:10:00 -0300 MIME-Version: 1.0 Date: Thu, 21 May 2009 22:33:47 -0700 Subject: categories: Reminder: Deadline for Special Issue of IMLA approaching (31st May 2009) From: Valeria de Paiva To: categories@mta.ca Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Valeria de Paiva Message-Id: Status: O X-Status: X-Keywords: X-UID: 43 Dear colleagues, The deadline for the submission of papers to the special issue of Information and Computation on Intuitionistic Modal Logics and Applications is fast approaching (31st May). Please see the CFP below, and forward it to other interested colleagues. If you'd like to submit a paper, but don't think you can make the deadline, please write to us with your title and preliminary abstract and we can have (some!) flexibility. Best regards, Brigitte & Valeria ------------------------------------------------------------------------ Call for Papers Special Issue of Information and Computation on Intuitionistic Modal Logics and Applications (IMLA) Guest Editors: Valeria de Paiva, Brigitte Pientka and Aleks Nanevski Submission deadline: 31. May, 2009 Constructive modal logics and type theories are of increasing foundational and practical relevance in computer science. Applications are in type disciplines for programming languages, and meta-logics for reasoning about a variety of computational phenomena. Theoretical and methodological issues center around the question of how the proof-theoretic strengths of constructive logics can best be combined with the model-theoretic strengths of modal logics. Practical issues center around the question of which modal connectives with associated laws or proof rules capture computational phenomena accurately and at the right level of abstraction and how to implement these efficiently. There have been a series of LICS-affiliated workshops devoted to the theme. The first one was held as part of FLoC1999, Trento, Italy, the second was part of FLoC2002, Copenhagen, Denmark, the third was associated with LiCS2005, Chicago, USA and the last one was associated with LICS 2008 in Pittsburgh, PA, USA. Two special issues of journals on the theme have already appeared, a Mathematical Structures in Computer Science volume edited by Matt Fairtlough, Michael Mendler and Eugenio Moggi (Modalities in type theory) in 2001, and a special issue of the Journal of Logic and Computation in 2004 (Intuitionistic Modal Logics and Application, eds. Valeria de Paiva, R. Gore ad M. Mendler). We are hereby soliciting papers for a further special volume of Information and Computation, devoted to Intuitionistic Modal Logics and Applications. We hope to cover the novel applications presented in the last two workshops, especially applications to computer security, automated deduction and computational linguistics, but also to include work not presented at the workshops. The proposed timeline of events is as follows: * Papers (preferably under 20 pages long) should be submitted by 31st May 2009 * Reviews will be provided until the end of August 2009 and the volume should be ready by the end of the Fall. Topics of interest include, but are not limited to: * applications of intuitionistic necessity and possibility * monads and strong monads * constructive belief logics and type theories * applications of constructive modal logic and modal type theory to formal verification, foundations of security, abstract interpretation, and program analysis and optimization * modal types for integration of inductive and co-inductive types, higher-order abstract syntax, strong functional programming * models of constructive modal logics such as algebraic, categorical, Kripke, topological, and realizability interpretations * notions of proof for constructive modal logics * extraction of constraints or programs from modal proofs * proof search methods for constructive modal logics and their implementations. Please contact one of the editors (Valeria de Paiva valeria@cuill.com or Brigitte Pientka bpientka@cs.mcgill.ca) if you're not sure that your paper is within the scope of this special volume. Submissions should be 10 to 20 pages long and sent in PostScript or PDF format to one of the editors, before the 31st May 2009. From rrosebru@mta.ca Sun May 24 12:03:16 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:03:16 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FDe-0004fk-3R for categories-list@mta.ca; Sun, 24 May 2009 12:02:34 -0300 Date: Fri, 22 May 2009 09:58:11 -0500 Subject: categories: Re: sketch theory From: Charles Wells To: Andre.Rodin@ens.fr, catbb Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Charles Wells Message-Id: Status: O X-Status: X-Keywords: X-UID: 44 I have not kept up with the field very well, but I can recommend these works: Peter Johnstone, *Sketches of an Elephant*, Vol. 2, OUP 2003: the chapter on sketches. (I am in rural Wisconsin at the moment asnd don't have access to the book. If OUP would make its pages available to look at on Amazon I could have told you the exact page.) Bagchi and Wells, *Graph Based Logic and Sketches*, here: http://arxiv.org/PS_cache/arxiv/pdf/0809/0809.3023v1.pdf Also Kinoshita, et al 1997, referred to in GBLS. There might be relevant papers since 1993 mentioned in the Elephant, too. Category people: If you can suggest other papers that should be included, let me know soon, and I will revise the sketches paper to include them (and the ones I mentioned above). Charles Wells On Wed, May 20, 2009 at 4:23 PM, wrote: > Dear Charles and others: > > this > > http://www.cwru.edu/artsci/math/wells/pub/pdf/sketch.pdf > > is your very useful overview of Sketch theory dated back to 1993. I wonder > how > much it omits today: are there significant research programmes in this > field > emerged during last 15 years? What should I look at first of all? Many > thanks > in advance. > > Andrei > > From rrosebru@mta.ca Sun May 24 12:03:17 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:03:17 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FCB-0004c7-U4 for categories-list@mta.ca; Sun, 24 May 2009 12:01:04 -0300 Date: Fri, 22 May 2009 09:29:48 -0500 Subject: categories: Re: sketch theory From: Charles Wells To: John Baez , catbb Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Charles Wells Message-Id: Status: O X-Status: X-Keywords: X-UID: 45 That is carried out (rather sketchily :)) on page 48 of Graph Based Logic and Sketches by Bagchi and Wells, here: http://arxiv.org/PS_cache/arxiv/pdf/0809/0809.3023v1.pdf This post http://sixwingedseraph.wordpress.com/2009/05/08/turning-definitions-into-mathematical-objects/ is the first of a projected series to explain the Bagchi-Wells paper in a more how-to-think-about-it style. Charles Wells On Thu, May 21, 2009 at 2:43 PM, John Baez wrote: > Dear Categorists - > > Andrei Rodin pointed out this paper by Charles Wells: > > http://www.cwru.edu/artsci/math/wells/pub/pdf/sketch.pdf > > I took a look. In section 4.1 it mentions that people have given a finite > limits sketch for cartesian closed categories. I'm curious about how this > works, Unfortunately the list of references given here is quite long. Can > anyone help me find a reference on a sketch for CCC's? > > Best, > jb > From rrosebru@mta.ca Sun May 24 12:03:17 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:03:17 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FBM-0004a1-8Q for categories-list@mta.ca; Sun, 24 May 2009 12:00:12 -0300 MIME-Version: 1.0 Date: Fri, 22 May 2009 16:20:48 +0200 Subject: categories: Re: Prof From: Urs Schreiber To: Thomas Hildebrandt , categories Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-PMX-Version: 5.4.6.354141, Antispam-Engine: 2.6.1.350677, Antispam-Data: 2009.5.22.140733 X-PerlMx-Spam: Gauge=IIIIIII, Probability=8%, Report='BODY_SIZE_1600_1699 0, BODY_SIZE_2000_LESS 0, BODY_SIZE_5000_LESS 0, BODY_SIZE_7000_LESS 0, WEBMAIL_SOURCE 0, __BOUNCE_CHALLENGE_SUBJ 0, __C230066_P1_5 0, __CP_URI_IN_BODY 0, __CT 0, __CTE 0, __CT_TEXT_PLAIN 0, __FRAUD_419_WEBMAIL 0, __FRAUD_419_WEBMAIL_FROM 0, __HAS_MSGID 0, __HELO_GMAIL 0, __MIME_TEXT_ONLY 0, __MIME_VERSION 0, __PHISH_SPEAR_STRUCTURE_1 0, __RDNS_GMAIL 0, __SANE_MSGID 0, __TO_MALFORMED_2 0' Sender: categories@mta.ca Precedence: bulk Reply-To: Urs Schreiber Message-Id: Status: O X-Status: X-Keywords: X-UID: 46 Hi, Mike Stay asked: > > The bicategory of (small categories, profunctors, and natural > > transformations), should be equivalent to the 2-category of (presheaf > > categories, colimit-preserving functors, and natural transformations). > > Has someone proved this? If so, where? Thomas Hildebrandt replied: > You may have a look at Prop. 4.2.4 in the PhD thesis of Gian Luca > Cattani from BRICS, University of Aarhus, available at > http://www.daimi.au.dk/~luca/thesis.html I am guessing that the crucial statement that makes this work is the standard fact that if a category A admits small colimits, then there is an equivalence of categories Funct^cocont(PSh(C), A) = Funct(C,A) . In the textbook literature one can find this for instance as corollary 2.7.4, page 63 of Kashiwara-Schapira's "Categories and Sheaves". It may be noteworthy that this statement is known to generalize from categories to (oo,1)-categories, for instance as given in theorem 5.1.5.6 of Lurie's "Higher Topos Theory". Colimit preserving functors between "presentable (oo,1)-categories", i.e between localizations of (oo,1)-presheaf categories play a major role in the theory and have some nice applications. For instance Ben-Zvi/Francis/Nadler have recently shown that "integral transforms" (of the Fourier-Mukai type and higher generalizations) are precisely equivalent to colimit preserving functors between the corresponding presentable (oo,1)-categories. See around the highlighted box in section 4 here: http://ncatlab.org/nlab/show/geometric+infinity-function+theory. Best, Urs From rrosebru@mta.ca Sun May 24 12:03:17 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:03:17 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FCr-0004dW-Dk for categories-list@mta.ca; Sun, 24 May 2009 12:01:45 -0300 Date: Fri, 22 May 2009 15:38:15 +0100 From: Steve Vickers To: John Baez , categories@mta.ca Subject: categories: Re: sketch theory Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Steve Vickers Message-Id: Status: O X-Status: X-Keywords: X-UID: 47 Dear John, Barr & Wells "Toposes, Triples and Theories", Section 4.4, give some examples of LE-sketches (= finite limit sketches) that includes sketches for the theories of finite limit categories and of elementary toposes. They don't include CCCs, but you should at least get the idea. The basic trick (corresponding to the logical one of Freyd's "essentially algebraic" theories) is to think of these theories as being given algebraically with some of the operators (e.g. composition, pairing) being partial and with domain of definition described by equations. You then introduce those domains of definitions as nodes in the sketch, with arrows, diagrams and cones constraining them to be finite limits in a way that corresponds to the equations. Incidentally, Palmgren and I recently came up with a new logical characterization of finite limit theories, using a logic of partial terms. It leads to a neat proof of the initial model theorem. However, I also believe there is a specific but non-obvious advantage of sketches over logical syntax in that sketches do not rely on having canonical finite limits. Suppose a sketch has two distinct nodes a and b, and manages to constrain them both to be finite limits of the same diagram. In a model, a and b can be interpreted as different objects (though, of course, they have to be isomorphic). Regards, Steve Vickers. John Baez wrote: > Dear Categorists - > > Andrei Rodin pointed out this paper by Charles Wells: > > http://www.cwru.edu/artsci/math/wells/pub/pdf/sketch.pdf > > I took a look. In section 4.1 it mentions that people have given a finite > limits sketch for cartesian closed categories. I'm curious about how this > works, Unfortunately the list of references given here is quite long. Can > anyone help me find a reference on a sketch for CCC's? > > Best, > jb > > From rrosebru@mta.ca Sun May 24 12:04:04 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:04:04 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FF2-0004kZ-Dr for categories-list@mta.ca; Sun, 24 May 2009 12:04:00 -0300 Date: Sat, 23 May 2009 02:44:26 +0200 From: Andre.Rodin@ens.fr To: Charles Wells , catbb Subject: categories: Re: sketch theory Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Andre.Rodin@ens.fr Message-Id: Status: O X-Status: X-Keywords: X-UID: 48 many thanks, Charles, somehow I forgot that the Elephant is also about Sk= etches. I came across this recent paper by Diskin&Wolter http://www.cs.toronto.edu/~zdiskin/Pubs/ACCAT-07.pdf where the authors propose a version of sketch-based syntax for Computer S= cience purposes. The main idea here (as far as I understood the paper) is to use sketches as arities of predicates. I heard about similar ideas from Rene Guitart in private conversations (but Rene's approach is algebraic rather= than logical). Looking at GBLS briefly I couldn't immediately grasp if your an= d Atish Bagchi's approach to graph-based logic is based on similar ideas or= your approach is quite different. I certainly should read GBLS more carefully = for discussing it but I would grateful for a hint. Andrei Selon Charles Wells : > I have not kept up with the field very well, but I can recommend these > works: > > Peter Johnstone, *Sketches of an Elephant*, Vol. 2, OUP 2003: the chapt= er on > sketches. (I am in rural Wisconsin at the moment asnd don't have acces= s to > the book. If OUP would make its pages available to look at on Amazon I > could have told you the exact page.) > > Bagchi and Wells, *Graph Based Logic and Sketches*, here: > > http://arxiv.org/PS_cache/arxiv/pdf/0809/0809.3023v1.pdf > > Also Kinoshita, et al 1997, referred to in GBLS. There might be releva= nt > papers since 1993 mentioned in the Elephant, too. > > Category people: If you can suggest other papers that should be includ= ed, > let me know soon, and I will revise the sketches paper to include them = (and > the ones I mentioned above). > > Charles Wells > > From rrosebru@mta.ca Sun May 24 12:05:12 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:05:12 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FG7-0004pG-Ho for categories-list@mta.ca; Sun, 24 May 2009 12:05:07 -0300 MIME-Version: 1.0 Date: Fri, 22 May 2009 22:30:01 -0400 Subject: categories: Re: sketch theory From: Zinovy Diskin To: "Andre.Rodin" , Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Zinovy Diskin Message-Id: Status: O X-Status: X-Keywords: X-UID: 49 Dear Andrei, Speaking about research programmes, Makkai's generalized sketches should definitely be mentioned. An easy introduction can be found in A Diagrammatic Logic for Object-Oriented Visual Modeling Zinovy Diskin and Uwe Wolter DOI Bookmark: 10.1016/j.entcs.2008.10.041 It provides references to Makkai's papers and some other sources, and briefly describes some history and motivations. You may skip all sentiments about engineering applications, or do just the opposite -- pay attention to them -- at least, this is what granting agencies like. There are two distinctions from Makkai's sketches: a signature of diagram predicates is a category rather than a set, and semantics is given in terms of functors into sketches rather than from them. ZD 2009/5/20 Andre.Rodin : > Dear Charles and others: > > this > > http://www.cwru.edu/artsci/math/wells/pub/pdf/sketch.pdf > > is your very useful overview of Sketch theory dated back to 1993. I wonder how > much it omits today: are there significant research programmes in this field > emerged during last 15 years? What should I look at first of all? Many thanks > in advance. > > Andrei > > > > From rrosebru@mta.ca Sun May 24 12:05:53 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:05:53 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FGl-0004sY-JP for categories-list@mta.ca; Sun, 24 May 2009 12:05:47 -0300 From: Thomas Streicher Date: Sat, 23 May 2009 16:13:25 +0200 To: categories@mta.ca Subject: categories: call for papers, constructive math meeting Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: Thomas Streicher Message-Id: Status: O X-Status: X-Keywords: X-UID: 50 Bob Lubarsky has asked to me to put the announcement below on the categories mailing list. Thomas SECOND ANNOUNCEMENT AND CALL FOR PAPERS Workshop and AMS Special Session on Constructive Mathmematics Florida Atlantic University Boca Raton, FL Oct 28 - Nov 1 2009 http://math.fau.edu/Richman/Worshop/ The workshop sessions will meet W Oct 28 & R Oct 29. Its goal will be actual progress in the field. The sessions and their leaders will be algebra (Fred Richman), analysis (Doug Bridges), topology (Bas Spitters), and set theory (Michael Rathjen). It will conclude the morning of F Oct 30 with a talk by Vladimir Lifschitz on constructive mathematics and computer science aimed at a general mathematics audience. The special session will be part of the AMS sectional meeting at FAU, F Oct 30 - Sun Nov 1, web site http://www.ams.org/amsmtgs/2161_program.html. Abstracts of talks to be considered for inclusion at this special session can be submitted over this AMS website, or at http://www.ams.org/cgi-bin/abstracts/abstract.pl, with a strict deadline of July 14. PLEASE NOTE THAT THIS DEADLINE IS EARLIER THAN THE ONE FOR NON-SPECIAL SESSION CONTRIBUTIONS!!! By the AMS standard, talks at such sessions are typically twenty minutes long. The organizing committee is Robert Lubarsky and Fred Richman. For further information contact Robert.Lubarsky@comcast.net. For further information on the AMS sectional meeting contact either Matthew Miller, the relevant AMS secretary, at miller@math.sc.edu, or Mario Milman, the local organizer, at extrapol@bellsouth.net. From rrosebru@mta.ca Sun May 24 12:06:43 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 12:06:43 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8FHa-0004xn-1g for categories-list@mta.ca; Sun, 24 May 2009 12:06:38 -0300 From: Hasse Riemann To: Category mailing list Subject: categories: Famous unsolved problems in ordinary category theory Date: Sat, 23 May 2009 20:14:02 +0000 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Hasse Riemann Message-Id: Status: O X-Status: X-Keywords: X-UID: 51 Hi all categorists =20 Here are other questions i think about and need your help with. =20 4> Are there any famous unsolved problems in category theory not related to h= igher dimensional category theory (but monoidal categories are ok as categories)? =20 Best regards Rafael Borowiecki From rrosebru@mta.ca Sun May 24 13:01:36 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Sun, 24 May 2009 13:01:36 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8G87-0000RH-Cx for categories-list@mta.ca; Sun, 24 May 2009 13:00:55 -0300 Date: Sat, 23 May 2009 19:20:30 -0400 (EDT) From: Robert Seely To: Categories List Subject: categories: Makkaifest Workshop 18 June 09 (McGill) Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Robert Seely Message-Id: Status: O X-Status: X-Keywords: X-UID: 52 Makkaifest Workshop 18 June 2009 Burnside Hall, McGill University [Updated information] We are pleased to announce the following workshop, held at McGill University, Mathematics Department, on 18 June 2009, in conjunction with the Makkaifest being held at CRM, 19-20 June 2009, with an initial reception at the CRM on 18 June. This workshop is intended for the participants of the Makkaifest. It will begin at 9am, in Burnside Hall, McGill University, and will finish around 5pm, so there will be time to get to the reception at CRM at 6pm. A provisional schedule of talks appears online: http://www.math.mcgill.ca/rags/seminar/mf-wkshop.html (Not all speakers have confirmed their participation, so please check the webpage for updated information.) Information about the weather and maps of the area (showing Burnside Hall) are given on the same webpage. The workshop will be an informal affair - there will be no registration, and no "refreshments" (people can buy their own coffee, and lunch will be "dutch treat"). The workshop is not officially part of the Makkaifest at the CRM. If you are interested in attending the workshop, please let us (Phil Scott or Robert Seely) know so we can be sure we have a room of suitable size. The themes of the workshop are those of the Makkaifest itself, and reflect interests shown by Michael Makkai over his career. Information about the Makkaifest (19-20 June at CRM) may be found on the meeting website: http://www.crm.umontreal.ca/Makkaifest09/ You can register for that meeting online, and if you plan to attend the meeting banquet on 19 June, please make sure we know (so we can inform the restaurant of the correct number). --- Phil Scott (phil@site.uottawa.ca) Robert Seely (rags@math.mcgill.ca) -- From rrosebru@mta.ca Mon May 25 11:04:25 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 11:04:25 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8alX-00014Z-AI for categories-list@mta.ca; Mon, 25 May 2009 11:02:59 -0300 Date: Sun, 24 May 2009 16:10:12 -0500 Subject: categories: Diagammes, Ehresmann Supplements to Cahiers From: Keith Harbaugh To: categories@mta.ca Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Keith Harbaugh Message-Id: Status: O X-Status: X-Keywords: X-UID: 53 With the recent question about references for sketch theory in mind, perhaps now is a good time to ask: Are the old issues of Diagrammes available anywhere on the web? Also, although the regular issues of the Cahiers seem to be available at http://www.numdam.org/numdam-bin/feuilleter?j=CTGDC, what about the Supplements, containing the collected work of Charles Ehresmann, published around 1982? Best wishes, Keith From rrosebru@mta.ca Mon May 25 11:57:01 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 11:57:01 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8bbV-0005BZ-2j for categories-list@mta.ca; Mon, 25 May 2009 11:56:41 -0300 Date: Mon, 25 May 2009 09:21:56 +1000 Subject: categories: Re: sketch theory From: Steve Lack To: John Baez , categories Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Steve Lack Message-Id: Status: O X-Status: X-Keywords: X-UID: 54 Dear John, You ask about a sketch for cartesian closed categories. Have a look at at the paper "A presentation of topoi as algebraic relative to categories or graphs (Dubuc-Kelly, J. Alg. 81: 420-433, 1983). This describes something even tighter: the category of cartesian closed categories is monadic over the category of graphs. If you look at the description given in that paper, it clearly contains a sketch for cartesian closed categories (this depends heavily paper on the paper Algebres Graphique of Albert Burroni). In fact the Dubuc-Kelly paper also describes a notion of presentation for finitary monads on Cat; this was later developed by Kelly and Power into a fully-fledged theory of presentations for finitary enriched monads on locally finitely preseentable categories, in their paper " Adjunctions whose counits are coequalizers, and presentations of finitary enriched monads" (JPAA 89:163-179, 1993). Regards, Steve Lack. On 22/05/09 5:43 AM, "John Baez" wrote: > Dear Categorists - > > Andrei Rodin pointed out this paper by Charles Wells: > > http://www.cwru.edu/artsci/math/wells/pub/pdf/sketch.pdf > > I took a look. In section 4.1 it mentions that people have given a finite > limits sketch for cartesian closed categories. I'm curious about how this > works, Unfortunately the list of references given here is quite long. Can > anyone help me find a reference on a sketch for CCC's? > > Best, > jb > > From rrosebru@mta.ca Mon May 25 11:57:44 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 11:57:44 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8bcS-0005Gu-V5 for categories-list@mta.ca; Mon, 25 May 2009 11:57:41 -0300 Date: Sun, 24 May 2009 20:18:08 -0400 Subject: categories: Re: sketch theory From: Zinovy Diskin To: Andre.Rodin@ens.fr, Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: Zinovy Diskin Message-Id: Status: O X-Status: X-Keywords: X-UID: 55 Let me make a few clarifying remarks On Fri, May 22, 2009 at 8:44 PM, wrote: > I came across this recent paper by Diskin&Wolter > > http://www.cs.toronto.edu/~zdiskin/Pubs/ACCAT-07.pdf > > where the authors propose a version of sketch-based syntax for Computer S= cience > purposes. The main idea here (as far as I understood the paper) is to use > sketches as arities of predicates. I heard about similar ideas from Rene > Guitart in private conversations (but Rene's approach is algebraic rather= than > logical). our version of sketches is intended for use in software engineering, not only in computer science. The difference between them is like the difference between, say, electrical engineering and physics. Predicate arities may be objects of any a priori chosen good category, e.g., sketches built in a previous step, but this is not the main idea. Relation of Makkai's generalized sketches to classical sketches is, roughly, like relation of a general first-order theory a la Tarski to a particular family of theories like, e.g., lattice theory. The former provide a general framework, in which the user can define any theory she likes. The latter is a family of particular instantiations of the framework. The fact that this family is expressive enough to specify any structure is another story. A first-order signature contains operation and predicate symbols. Similarly, a generalized sketch signature may contain operation symbols too (whose arities are In-Out spans). Definitions and some details can be found in Report referenced as [6] in the paper above. ZD Looking at GBLS briefly I couldn't immediately grasp if your and > Atish Bagchi's approach to graph-based logic is based on similar ideas or= your > approach is quite different. I certainly should read GBLS more carefully = for > discussing it but I would grateful for a hint. > > Andrei > > > > Selon Charles Wells : > >> I have not kept up with the field very well, but I can recommend these >> works: >> >> Peter Johnstone, *Sketches of an Elephant*, Vol. 2, OUP 2003: the chapte= r on >> sketches. =C2=A0(I am in rural Wisconsin at the moment asnd don't have a= ccess to >> the book. =C2=A0If OUP would make its pages available to look at on Amaz= on I >> could have told you the exact page.) >> >> Bagchi and Wells, *Graph Based Logic and Sketches*, here: >> >> http://arxiv.org/PS_cache/arxiv/pdf/0809/0809.3023v1.pdf >> >> Also Kinoshita, et al 1997, referred to in GBLS. =C2=A0There might be re= levant >> papers since 1993 mentioned in the Elephant, too. >> >> Category people: =C2=A0If you can suggest other papers that should be in= cluded, >> let me know soon, and I will revise the sketches paper to include them (= and >> the ones I mentioned above). >> >> Charles Wells >> >> > > From rrosebru@mta.ca Mon May 25 11:58:16 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 11:58:16 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8bcz-0005Jc-Bt for categories-list@mta.ca; Mon, 25 May 2009 11:58:13 -0300 Date: Sun, 24 May 2009 23:02:46 -0400 From: Logic and Computational Complexity To: categories@mta.ca Subject: categories: LCC Extension/CfP Sender: categories@mta.ca Precedence: bulk Reply-To: Logic and Computational Complexity Message-Id: Status: O X-Status: X-Keywords: X-UID: 56 [ Please broadcast/post/forward. Apologies for duplicates] LCC'09 FINAL CALL FOR PAPERS >>> EXTENDED DEADLINE: JUNE 5 The Tenth International Workshop on Logic and Computational Complexity (LCC'09, www.cs.indiana.edu/lcc) will be held in Los Angeles on August 10, 2009, as an affiliated meeting of LiCS'09 (www2.informatik.hu-berlin.de/lics/lics09), and in conjunction with SAS'09 (sas09.cs.ucdavis.edu). LCC meetings are aimed at the foundational interconnections between logic and computational complexity, as present, for example, in implicit computational complexity (descriptive and type-theoretic methods); deductive formalisms as they relate to complexity (e.g. ramification, weak comprehension, bounded arithmetic, linear logic and resource logics); complexity aspects of finite model theory and databases; complexity-mindful program derivation and verification; computational complexity at higher type; and proof complexity. The LCC'09 program will consist of invited lectures as well as contributed papers selected by the program committee. This year there will be no published proceedings, and work submitted or published elsewhere is welcome, provided all pertinent information is disclosed at submission time. Papers should be written in English, be accessible to non-specialists, start with a clear statement of the issues and results, and not exceed 15 pages. Proposed papers should be uploaded to http://www.easychair.org/conferences/?conf=lcc090, by Friday, June 5, 2009, with expected notification date of Monday, June 22. For additional information see www.cs.indiana.edu/lcc, or email inquiries to lcc@cs.indiana.edu. Further information about previous LCC meetings can be found at http://www.cis.syr.edu/~royer/lcc. PROGRAM COMMITTEE * Patrick Baillot (CNRS-ENS Lyons, Co-chair) * Markus Lohrey (Leipzig, Co-Chair) * Albert Atserias (UP de Catalunya) * Pablo Barcelo (U de Chile) * Arnold Beckmann (Swansea) * Lauri Hella (Tampere) * Andrei Krokhin (Durham) * Chris Pollett (San Jose SU) STEERING COMMITTEE: Michael Benedikt (Oxford, Co-chair), Daniel Leivant (Indiana U, Co-chair), Robert Constable (Cornell), Anuj Dawar (Cambridge), Fernando Ferreira (Lisbon), Martin Hofmann (U Munich), Neil Immerman (U Mass. Amherst), Neil Jones (Copenhagen), Bruce Kapron (U Victoria), Jean-Yves Marion (LORIA Nancy), Luke Ong (Oxford), Martin Otto (Darmstadt), James Royer (Syracuse), Helmut Schwichtenberg (U Munich), and Pawel Urzyczyn (Warsaw) From rrosebru@mta.ca Mon May 25 11:59:08 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 11:59:08 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8bdo-0005Nc-RU for categories-list@mta.ca; Mon, 25 May 2009 11:59:04 -0300 Date: Sun, 24 May 2009 22:03:44 -0700 Subject: categories: Re: sketch theory From: John Baez To: categories Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: John Baez Message-Id: Status: O X-Status: X-Keywords: X-UID: 57 Steve Lack writes: You ask about a sketch for cartesian closed categories. Have a look at > at the paper "A presentation of topoi as algebraic relative to categories > or > graphs (Dubuc-Kelly, J. Alg. 81: 420-433, 1983). This describes something > even tighter: the category of cartesian closed categories is monadic over > the category of graphs. > Thanks! And thanks to everyone else for their helpful comments. I'm behind on answering my emails. In this approach, does each pair of objects in a ccc come with a chosen product and exponential? Are the morphisms of ccc's are required to preserve these on the nose? At first I was a bit shocked to hear of a sketch for ccc's, because the internal hom is contravariant in one variable. But I guess that as long as we treat ccc's purely 1-categorically that's no problem. But then I guess we pay the price of "undue strictness". Right? Best, jb From rrosebru@mta.ca Mon May 25 11:59:41 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 11:59:41 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8beM-0005RE-6g for categories-list@mta.ca; Mon, 25 May 2009 11:59:38 -0300 Date: Mon, 25 May 2009 12:25:46 +0200 (CEST) From: Paul-Andre Mellies To: categories@mta.ca Subject: categories: postdoc position in Paris Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Paul-Andre Mellies Message-Id: Status: O X-Status: X-Keywords: X-UID: 58 ====================================================== Postdoctoral position in PPS (CNRS & University Paris 7) Curry-Howard and Concurrency Theory ====================================================== A 12-month postdoctoral position is available within the Laboratory PPS (Preuves Programmes Systemes) located at University Paris 7 Denis Diderot: http://www.pps.jussieu.fr/ The position is supported by the research project Curry-Howard and Concurrency Theory (CHOCO) funded by the French national research agency ANR. http://choco.pps.jussieu.fr/ Important dates: - deadline for application: May 31st 2009 - notification: June 15th 2009 - suggested starting date: September 1st 2009 Application procedure. Full application should be sent before May 31st 2009 including a resume, a short research project (1 page) and two names of possible references. This should be preferably done by email or at the postal address below. For all correspondance use the contact addresses: postdoc-choco@pps.jussieu.fr Paul-Andre Mellies Laboratoire PPS Universite Paris 7 - Denis Diderot Case 7014 75205 Paris Cedex 13 FRANCE The net salary will be around 2000 euro/month before income tax. The starting date for the postdoctoral position is September 2009 although later dates may be also considered. Description The general purpose of the project CHOCO is to investigate the syntactic, semantic and algebraic aspects of proof theory in order to integrate concurrency theory in the Curry-Howard correspondence between proofs and programs. The interdisciplinary nature of the project between proof theory and concurrency theory means that candidates from various scientific horizons are welcome to apply. On the other hand, we will consider with special interest applications by candidates with background in one or several of the fields: - linear logic (proof nets, geometry of interaction) - semantics (game semantics, vectorial semantics) - concurrency theory (process calculi, presheaf semantics) - type theory (realizability, types for process calculi) - rewriting theory (lambda-calculus, diagrammatic rewriting) - category theory (categorical algebra, topos theory) The applicant should hold a PhD or be about to defend his/her PhD thesis by December 2009. The postdoc researcher will work within the laboratory PPS (Preuves, Programmes, Systemes) http://www.pps.jussieu.fr which is internationally recognized as one of the leading research laboratories in mathematics and computer science, with its distinctive proof-theoretic culture. The laboratory PPS is located in Chevaleret, the largest research community of mathematicians in France. The laboratory PPS is also part of the Fondation Sciences Mathematiques de Paris. http://www.sciencesmath-paris.fr Strong interaction of the postdoc researcher with the partner sites of the CHOCO project is also expected: - Laboratoire d'Informatique de Paris Nord. - Laboratoire d'Informatique du Parallelisme, Lyon, - Laboratoire de Mathematiques de l'Universite de Savoie, Chambery - Institut de Mathematiques de Luminy, Marseille, - Laboratoire d'Informatique Fondamentale de Marseille, Further information will possibly be made available from the web page of the project indicated above. From rrosebru@mta.ca Mon May 25 12:00:46 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 12:00:46 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8bfD-0005Wb-QG for categories-list@mta.ca; Mon, 25 May 2009 12:00:32 -0300 From: "Ronnie Brown" To: Subject: categories: patenting colimits? Date: Mon, 25 May 2009 14:35:58 +0100 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: "Ronnie Brown" Message-Id: Status: O X-Status: X-Keywords: X-UID: 59 Larry Lambe passed on the following url to me for comment and I thought = it would be of interest to others on the category theory list, with more = expertise than I. I have not had time to study it, but on the face of = it, it seems like patenting mathematics, and to be deplored intensely. = Am I wrong?=20 http://www.freepatentsonline.com/6964037.html Title: Method and apparatus for determining colimits of hereditary diagrams=20 Document Type and Number: United States Patent 6964037=20 A computer-implemented method and system for determining colimits of = hereditary diagrams. A user specifies a diagram of diagram and specifies = performance of a colimit operation. Once the colimit is performed, the = name of the colimit is added to the hereditary diagram. The described = embodiment supports diagrams of diagrams, also called hierarchical = diagrams. Ronnie http://www.freepatentsonline.com/6964037.html From rrosebru@mta.ca Mon May 25 12:02:49 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 12:02:49 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8bgH-0005dz-Nc for categories-list@mta.ca; Mon, 25 May 2009 12:01:37 -0300 Date: Mon, 25 May 2009 09:51:10 -0500 Subject: categories: Re: Diagammes, Ehresmann Supplements to Cahiers From: Charles Wells To: Keith Harbaugh , catbb Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Charles Wells Message-Id: Status: O X-Status: X-Keywords: X-UID: 60 Smith Library at Case Western Reserve University has many issues of the older Diagrammes. Or did in the 1990's. Charles Wells On Sun, May 24, 2009 at 4:10 PM, Keith Harbaugh wrote: > With the recent question about references for sketch theory in mind, > perhaps now is a good time to ask: > > Are the old issues of Diagrammes available anywhere on the web? > Also, although the regular issues of the Cahiers seem to be available at > > http://www.numdam.org/numdam-bin/feuilleter?j=CTGDC, > > what about the Supplements, containing the collected work of Charles > Ehresmann, > > published around 1982? > > > Best wishes, > > Keith From rrosebru@mta.ca Mon May 25 12:21:24 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 12:21:24 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8byS-0007e6-FT for categories-list@mta.ca; Mon, 25 May 2009 12:20:24 -0300 Date: Mon, 25 May 2009 09:53:36 -0500 Subject: categories: More about Diagrammes. From: Charles Wells To: catbb Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Charles Wells Message-Id: Status: RO X-Status: X-Keywords: X-UID: 61 That'll teach me to hit Send without proofreading. I should add that the copies of Diagrammes at CWRU should be available via interlibrary loan, but not over the web. Charles Wells, reakky, Wells. [Note from moderator: Charles - readers won't get your remark because I changed the Wekks you sent to Wells in the posting, but I like your response, and your point is very well well taken. I'll repeat it and add two other current items for readers: *proofread posts before sending* *do not endlessly quote previous posts in your replies (they are deleted before posting)* *DO NOT, yup I'm shouting, send attachments, html or other garbage - it takes time to delete, and offending posts are randomly discarded. Categories is a _text_ list* These points, several others, and other information are on the list page: http://www.mta.ca/~cat-dist/ but no one has read this far, have you? ] From rrosebru@mta.ca Mon May 25 19:42:31 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 19:42:31 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8iqp-0004Go-KS for categories-list@mta.ca; Mon, 25 May 2009 19:40:59 -0300 Date: Mon, 25 May 2009 18:13:10 +0200 From: Andree Ehresmann To: Keith Harbaugh , categories@mta.ca Subject: categories: Re: Diagammes, Ehresmann Supplements to Cahiers Content-Type: text/plain;charset=ISO-8859-1;DelSp="Yes";format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Andree Ehresmann Message-Id: Status: RO X-Status: X-Keywords: X-UID: 62 For the moment, I don't think issues of "Diagrammes" are available on the net, except for Guitart's papers which can be found on his site http://pagesperso-orange.fr/rene.guitart/index.html and for a short paper of myself available on my site http://pagesperso-orange.fr/ehres For the volumes of "Charles Ehresmann: Oeuvres completes et commentees" (Supplsements to the "Cahiers" 1980-83), NUMDAM has promised to post them, but not before several months because they have too many work ahead. Before that, I intend to publish on my site part of the "Comments" and "Synopsis" which I added to Charles' works during the editing of the 7 volumes. Kind regards Andree [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon May 25 19:59:27 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 19:59:27 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8j8R-0005EC-Rr for categories-list@mta.ca; Mon, 25 May 2009 19:59:11 -0300 Content-Type: text/plain; charset=ISO-8859-1; delsp=yes; format=flowed Content-Transfer-Encoding: quoted-printable From: =?ISO-8859-1?Q?Ren=E9_Guitart?= Subject: categories: Re: Diagammes, Ehresmann Supplements to Cahiers Date: Mon, 25 May 2009 18:52:25 +0200 To: Keith Harbaugh , categories@mta.ca Sender: categories@mta.ca Precedence: bulk Reply-To: =?ISO-8859-1?Q?Ren=E9_Guitart?= Message-Id: Status: O X-Status: X-Keywords: X-UID: 64 Dear Keith, concerning the twelve papers that I have published in Diagrammes, =20 they are on line in my page http://pagesperso-orange.fr/rene.guitart/ Best wishes, Ren=E9 Le 24 mai 09 =E0 23:10, Keith Harbaugh a =E9crit : > > With the recent question about references for sketch theory in mind, > perhaps now is a good time to ask: > > Are the old issues of Diagrammes available anywhere on the web? > Also, although the regular issues of the Cahiers seem to be =20 > available at > > http://www.numdam.org/numdam-bin/feuilleter?j=3DCTGDC, > > what about the Supplements, containing the collected work of Charles > Ehresmann, > > published around 1982? > > > Best wishes, > > Keith > > > [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon May 25 20:04:47 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 20:04:47 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8jDe-0005Ws-Ep for categories-list@mta.ca; Mon, 25 May 2009 20:04:34 -0300 Date: Mon, 25 May 2009 11:53:47 -0700 From: Vaughan Pratt To: categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Vaughan Pratt Message-Id: Status: O X-Status: X-Keywords: X-UID: 65 On 5/25/2009 6:35 AM, Ronnie Brown wrote: > Larry Lambe passed on the following url to me for comment and I > thought it would be of interest to others on the category theory > list, with more expertise than I. I have not had time to study it, > but on the face of it, it seems like patenting mathematics, and to > be deplored intensely. Am I wrong? > > > http://www.freepatentsonline.com/6964037.html I skimmed the patent briefly just now, dated 2005. I was amused to see Dusko Pavlovic's name on it, I hadn't realized Dusko had become an inventor (congrats, Dusko). My first impression was that it's patenting the application of a category theory technique to the composition of hierarchically organized software specifications. It wasn't immediately clear to me which claims in the patent someone "skilled in the art" wouldn't have come up with right away given the problem(s) claimed to have been overcome. Since simply aggregating things is an obvious technique, the role of the morphisms in regulating the overlaps in the aggregation is obviously key. That of course is far too well known to be patentable itself. What I couldn't find on a first pass was what problem was overcome by what clever *and novel* trick. As with any patent, its viability will depend on how original the application is. Any prior art applying it in this way will render it vulnerable, but if the method is sufficiently novel it may serve its intended purpose of temporarily (namely until 2025) barring entry of others to whatever market turns out to have been created by this application, unless the would-be competitor can come up with a satisfactory alternative that does not infringe on this patent. (Imagine a jury wrestling with the question of whether amalgamation as used in logic and algebra infringes on a patent based on colimits.) Mathematicians who are philosophically opposed to seeing their ideas put to use in the business world should either stick to those parts of mathematics least likely to be of practical use or prepare for the shock of seeing their ideas used for the benefit of the non-mathematical public in ways that enrich primarily the "last-mile" people bringing those ideas to the public. In the first two decades of the internet, some academics took the attitude that no one should derive commercial benefit from the internet, and protested strenuously whenever anyone appeared to be trying to do so. That dam burst around 1995, and the purists were run over in the resulting stampede. There is no point trying to stand in the way of a similar stampede for commercial applications of category theory. Either colimits will turn out not to be a particularly effective way of assembling software specifications, in which case the patent will have been a waste of money, or they will turn out to be of use, in which case the purists will (hopefully) be run over as they were for the internet. More importantly from the perspective of mathematics, the latter outcome will motivate the funding agencies to take category theory more seriously and steer more support in its direction so it can grow faster and be even more useful. This would make category theory a secondary beneficiary behind the primary "last-mile" beneficiaries, giving it a more engineering flavour that brings it closer to the standing of academic electrical engineering and computer science, whose status is that of secondary beneficiaries of practical applications behind such primary beneficiaries as Oracle and HP. This connection with practicality has not impeded theoretical computer science, which has done quite well in the reflected glory of usefulness to the public at large. The biggest risk to which this patent subjects category theory is that if it fails to benefit its assignee, Kestrel, for want of interest in its methods, then that outcome might be used in arguments against raising the funding level for category theory research. Funding might then stay at the low level appropriate for truly pure mathematics, pure in Hardy's sense of having no practical application, just enough to support the most talented contributors to the subject while encouraging the rest to apply their enthusiasm for mathematics to areas of greater public benefit. Mathematicians wanting to prevent business people from applying mathematical results to practical problems via the usual protocols of the business world (e.g. patents) for fear it will somehow impede or impurify mathematics are like parents wanting to prevent doctors from disease-proofing their kids via the usual protocols of the medical world (e.g. vaccination) for fear it will somehow cause autism or turn their kids into needle-using junkies. The arguments that there are better protocols than patents or vaccination are not widely accepted today in the respective professional communities currently using them, though of course that sort of thing can change with the advent of new insights and better methods. Vaughan Pratt [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon May 25 20:05:31 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 20:05:31 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8jEW-0005aO-TN for categories-list@mta.ca; Mon, 25 May 2009 20:05:28 -0300 Date: Mon, 25 May 2009 14:11:55 -0700 From: Toby Bartels To: categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: Toby Bartels Message-Id: Status: O X-Status: X-Keywords: X-UID: 66 Ronnie Brown wrote: >Larry Lambe passed on the following url to me for comment and I thought it would be of interest to others on the category theory list, with more expertise than I. I have not had time to study it, but on the face of it, it seems like patenting mathematics, and to be deplored intensely. Am I wrong? >http://www.freepatentsonline.com/6964037.html >[...] It is certainly to be deplored, but I'm not sure that it's anything new. "A computer-implemented method and system for" performing calculations is a common patent; there are even patents on straight-up algorithms. The U.S. patent office is far too ignorant to judge whether the idea "would have been obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains" (35 U.S.C. 103), which would make the invention unpatentable. Certainly much of what is in the patent application is obvious, but perhaps not all of it; were these diagrams of diagrams a new idea?, or was applying them to computer system specifications a new idea?. If so, it's too bad if they're published here instead of in a journal. But actually, that doesn't seem to be what the patent is about; it spends more time explaining how to calculate colimits of graphs and repeating the rather obvious 3-option user menu. There is an interesting theorem about extensions of diagrams; I trust that it was published in one of the cited journal articles. As (at least) one of the listed inventors is a reader of the list, we might hear the other side; I'd be interested. --Toby [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon May 25 20:06:46 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 25 May 2009 20:06:46 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M8jFi-0005fn-4O for categories-list@mta.ca; Mon, 25 May 2009 20:06:42 -0300 Date: Tue, 26 May 2009 08:09:03 +1000 Subject: categories: Re: sketch theory From: Steve Lack To: John Baez , categories Content-type: text/plain; charset="US-ASCII" Content-transfer-encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Steve Lack Message-Id: Status: O X-Status: X-Keywords: X-UID: 67 On 25/05/09 3:03 PM, "John Baez" wrote: > Steve Lack writes: > > You ask about a sketch for cartesian closed categories. Have a look at >> at the paper "A presentation of topoi as algebraic relative to categories >> or >> graphs (Dubuc-Kelly, J. Alg. 81: 420-433, 1983). This describes something >> even tighter: the category of cartesian closed categories is monadic over >> the category of graphs. >> > > Thanks! > > And thanks to everyone else for their helpful comments. I'm behind on > answering my emails. > > In this approach, does each pair of objects in a ccc come with a chosen > product and exponential? Are the morphisms of ccc's are required to preserve > these on the nose? Yes, that's right on both counts, but see below. > > At first I was a bit shocked to hear of a sketch for ccc's, because the > internal hom is contravariant in one variable. But I guess that as long as > we treat ccc's purely 1-categorically that's no problem. But then I guess > we pay the price of "undue strictness". Right? As you say, if you work 1-categorically, you are stuck with undue strictness. And as you imply, there is an impediment to a fully 2-categorical approach because of the contravariance of the internal hom. But there is a way around this. You work 2-categorically, but not over the 2-category Cat, but over the 2-category of categories, functors, and natural _isomorphisms_. (Kelly & co call this 2-category Cat_g, with g presumably standing for groupoidal, since this is not just enriched in Cat but in groupoids.) Then the internal hom does indeed become a 2-functor Cat^2_g-->Cat_g. Having these invertible 2-cells now allows you to consider pseudomorphisms of algebras, which preserve structure up to isomorphism, thus alleviating the problem of undue strictness. It doesn't completely solve it - since we only have invertible 2-cells, we don't have a notion of lax morphism; or, more precisely, the notion of lax morphism we get is just that of pseudomorphism. Similarly, some constructions might not give what we hoped for. For example, the cotensor C^2 in Cat_g is not the category of arrows in C, it's the category of invertible arrows in C. All the best, Steve. [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Tue May 26 22:16:50 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 26 May 2009 22:16:50 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M97j0-0003oW-EJ for categories-list@mta.ca; Tue, 26 May 2009 22:14:34 -0300 Date: Mon, 25 May 2009 19:53:45 -0400 (EDT) From: Michael Barr To: Vaughan Pratt , categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Michael Barr Message-Id: Status: O X-Status: X-Keywords: X-UID: 68 Interesting comments by Vaughan. I have not looked at this patent and have no intention of doing so. But Charles and I, both in CTCS and in a paper published in some CS conference proceedings exhibited things like a sketch for trees of integers as a pushout or amalgamated sum of a sketch for trees and that for integers by identifying the sort for integers in the latter with the sort for leaves in the fomer. I think we have a triple amalgamation too, something like trees of lists of integers. So evidence of prior art certainly exists, if anyone cares. On the other hand, I for one would welcome serious applications of category theory in industry. My former department is hiring in only three areas: number theory (in which they are truly strong), applied math, and statistics (in each of which I rather suspect they are truly weak since they are competing with every g-d university in North America). I would just love to shove it in their collective faces that by allowing the category theory group to wither, they have allowed an important applied area to disappear. But no, they would rather be in the rearguard than the advanced guard. Wouldn't it be nice to make the same point to NSF which announced officially in 1993 that there would never again be any funding in category theory? Michael [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Tue May 26 22:16:50 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 26 May 2009 22:16:50 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M97kr-0003vx-4C for categories-list@mta.ca; Tue, 26 May 2009 22:16:29 -0300 Date: Mon, 25 May 2009 17:04:37 -0700 From: Toby Bartels To: categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: Toby Bartels Message-Id: Status: O X-Status: X-Keywords: X-UID: 69 Vaughan, I agree with nearly all that you say about how good it would be if category theory found practical, commercially viable application. The only thing that I don't understand is why you see patenting it as a *good* thing, when (as you say) the purpose of a patent is >temporarily (namely until 2025) barring entry of others >to whatever market turns out to have been created by this application, that is, to *prevent* (in part) commercial application. I can only suppose that this is because patents are one of >the usual protocols of the business world along with many other anti-competitive practices. (Interestingly, software patents are unavailable in much of the world, so I'm not sure that it really makes sense to call them "usual".) I know that if *I* ever come up with a commercially viable application (ha!), I would not wanted to be hobbled by a patent on the relevant mathematics. --Toby [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Tue May 26 22:16:50 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 26 May 2009 22:16:50 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M97kG-0003uC-Hm for categories-list@mta.ca; Tue, 26 May 2009 22:15:52 -0300 Date: Mon, 25 May 2009 17:04:10 -0700 Subject: categories: Re: patenting colimits? From: Greg Meredith To: Toby Bartels , categories@mta.ca Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Greg Meredith Message-Id: Status: O X-Status: X-Keywords: X-UID: 70 Toby, et al, Unfortunately, the patent game is more subtle than 'is it really new' on adjudication. To the best of my understanding, the adjudication process over a disputed claim really has a lot more to do with the depth of the pockets of the parties involved in the dispute. Discovery and argumentation can often be drawn out in a manner that those not quite resourced to see through to the end of the process simply get buried. The organizations and entities engaged in the IP-game are fully aware of this aspect of the whole arrangement. While i'm of mixed feelings regarding the overall issue of intellectual property, the actual motivations and carryings on of those who do engage in this really are often quite deplorable. Best wishes, --greg On Mon, May 25, 2009 at 2:11 PM, Toby Bartels < toby+categories@ugcs.caltech.edu >wrote: > Ronnie Brown wrote: > > >Larry Lambe passed on the following url to me for comment and I thought it > would be of interest to others on the category theory list, with more > expertise than I. I have not had time to study it, but on the face of it, > it seems like patenting mathematics, and to be deplored intensely. Am I > wrong? > >http://www.freepatentsonline.com/6964037.html > >[...] ... [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Tue May 26 22:17:39 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 26 May 2009 22:17:39 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M97lu-00040t-Sb for categories-list@mta.ca; Tue, 26 May 2009 22:17:34 -0300 Date: Mon, 25 May 2009 22:20:10 -0300 From: "Eduardo J. Dubuc" To: Vaughan Pratt , categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: "Eduardo J. Dubuc" Message-Id: Status: O X-Status: X-Keywords: X-UID: 71 if they want to patent, let them patent !! [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Tue May 26 22:18:17 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 26 May 2009 22:18:17 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M97mX-00044A-He for categories-list@mta.ca; Tue, 26 May 2009 22:18:13 -0300 Date: Tue, 26 May 2009 05:46:09 +0100 (BST) From: Dusko Pavlovic To: Toby Bartels , categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Dusko Pavlovic Message-Id: Status: O X-Status: X-Keywords: X-UID: 72 hi. On Mon, 25 May 2009, Toby Bartels wrote: > Ronnie Brown wrote: [snip] >> it seems like patenting mathematics, and to be deplored >> intensely. >> [...] > I trust that it was published in one of the cited journal articles. > > As (at least) one of the listed inventors is a reader of the list, > we might hear the other side; I'd be interested. yes, i stand guilty as accused: we patented colimits. but just the *hereditary* ones. so if you compute 1+1, you don't owe me anything. but if you compute 1+(1+0), then expect a letter from my lawyers, the same ones representing MPAA, RIAA and elsevier. but those 1s that you are computing with must be software specifications, ie in the form "spec 1 endspec", or something like that... in fact i prolly shouldn't be joking about this. patent laws are a deadly serious symptom. speaking of diseases, do you know that about 30% of human genome is patented? most of the potential cancer and parkinson disease genes are owned by a couple of companies. that means that if i want to test whether i have some cancer-related gene, i have to go to a lab that has the monopoly on testing that gene (since they rarely license to others). they will charge me a monopoly price, and if i want to test 5 genes, i may have to write to 5 different labs. if i want a second opinion about the test, whoever gives it to me may be sued. and there is no second test. the motivation for this statute is that it provides incentives for research. in contrast with the genes, mathematics cannot be patented, nor copyrighted, even according to the current crazy laws. officially and explicitly not. if you say in a patent application that you have this extremely original result, which never occurred to anyone else, and you would like to patent it --- they will reject it. the same with copyright: if you try to copyright a theorem, it will not work: anyone can cite your theorem without paying you. *but* if you write a book, and present pythagora's theorem in it, you will not only be able to copyright it, but it will actually be almost impossible for you to distribute your book without copyright it, and without selling the copyright to a publisher. so anyone who wants to use your version of pythagoras' theorem has to ask your publisher's permission. patents are crazier than copyright --- but maybe not that much crazier. you cannot patent mathematics, but you can patent "method and apparatus" for a particular application of pythagoras' theorem. (they always call it "method and apparatus".) you cannot patent modular exponentiation, nor the conjecture that inverting it (ie computing the discrete logarithms) is computationally unfeasible. but you can patent a method and apparatus to share a public key by exchanging and multiplying two modular exponents. the essence of your originality argument will rely upon the novel use of the conjecture that the discrete logarithms are hard to compute, on which the security of your system is based. what i just described is the *diffie-hellman* patent of public key cryptography. it may sound crazy to pure mathematicians, but there is very little doubt that the diffie-hellman invention changed the world of cryptography, networks, the web. our banks would work differently without diffie-hellman. (ironically, it turned out that some british civil servants working at GCHQ discovered the diffie-hellman discovery 9 years before diffie and hellman, see http://jya.com/nsam-160.htm but the UK governement classified it all, and even paid royalties for the diffie-hellman patent.) our colimits patent was, of course, not of comparable importance, although the underlying math was perhaps slightly less obvious. i'll only comment about it because toby asked. many people in software specification community (starting with goguen and burstall) thought that colimits were a good tool for composing sofware specifications. the objects of the category where you are computing the colimits are theories in some formal language, and the morphisms are the interpretations that map axioms to theorems. many people studied that approach, and a couple of tools really used it. but when you really start building software with such a tool, you find that the method hampers software reuse and evolution: a colimit composes your components by cooking them up into a big unreadable specification. so you find yourself saving the diagram of your colimit all the time, and trying to relate the content of the colimit spec with its nodes. (which ironically repeats the first lesson about the colimits: the colimit is not just the tip of the cocone, but the whole thing.) anyway, instead of computing the colimits of specs and then building new diagrams of the resulting unreadable specs to compute even more unreadable (and unmodifiable!) specs as colimits, we wanted to build a category where the objects would be diagrams of diagrams of diagrams... of specs, and the morphisms would be such that each diagram (of diagrams...) would be a colimit of itself, when externalized. that is what the requirement of a non-destructive colimit operation amounts to. what is patented is not that category, but the method to implement and use it to build and maintain software specs. we did some of implementing and using, and some of it was fun, but definitely not the shortest way to building the kind of software that needed to be built. i don't think that we published anything about this construction. the patent description was written by the lawyer (a very bright woman, i think with an MIT PhD, who now runs the world for google). some other things that we didn't publish were perhaps closer to a mathematical result. but the purpose of it all was to build software, not to publish mathematical results. we just patented it so that all those geneticists have to pay us some day, or give us some free genetic testing in exchange for hereditary diagrams ;) -- dusko [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Tue May 26 22:19:24 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 26 May 2009 22:19:24 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M97nc-00049y-OT for categories-list@mta.ca; Tue, 26 May 2009 22:19:20 -0300 Date: Tue, 26 May 2009 15:56:37 -0600 (MDT) Subject: categories: Applying Category Theory to Improve ... From: mjhealy@ece.unm.edu To: categories@mta.ca Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: mjhealy@ece.unm.edu Message-Id: Status: O X-Status: X-Keywords: X-UID: 73 Our full account of an application of colimits and limits to improving upon a standard neural architecture is soon to appear in the journal Neurocomputing. In case this interests you, a preprint is obtainable fro= m my website, http://www.ece.unm.edu/~mjhealy , or else contact me for a copy. The blurb: Applying Category Theory to Improve the Performance of a Neural Architect= ure Michael J. Healy, Richard D. Olinger, Robert J. Young, Shawn E. Taylor, Thomas P. Caudell, and Kurt W. Larson Abstract: A recently-developed mathematical semantic theory explains the relationship between knowledge and its representation in connectionist systems. The semantic theory is based upon category theory, the mathematical theory of structure. A product of its explanatory capability is a set of principles to guide the design of future neural architectures and enhancements to existing designs. We claim that this mathematical semantic approach to network design is an effective basis for advancing the state of the art. We offer two experiments to support this claim. One of these involves multispectral imaging using data from a satellite camera. [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Tue May 26 22:20:27 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Tue, 26 May 2009 22:20:27 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M97oY-0004G3-S8 for categories-list@mta.ca; Tue, 26 May 2009 22:20:18 -0300 Date: Tue, 26 May 2009 18:10:54 -0700 (PDT) From: John MacDonald To: categories@mta.ca Subject: categories: FMCS 2009 SCHEDULE Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: John MacDonald Message-Id: Status: RO X-Status: X-Keywords: X-UID: 74 FMCS 2009 17th Workshop on Foundational Methods in Computer Science University of British Columbia, VANCOUVER, Canada MAY 28th - 31st, 2009 FINAL ANNOUNCEMENT * * * Last minute registration is possible. Registration forms are available from the conference webpage http://www.pims.math.ca/scientific/general-event/foundational-methods-computer-science-2009 Accommodations may also be reserved from the same page. FMCS 2009 SCHEDULE Thursday, May 28, 2009 3:00p.m. Gage residence rooms available for check-in 6:00p.m. Welcome Reception - Ruth Blair AB - Gage Residence Friday, May 29, 2009 Tutorial Sessions - WMAX 240 - 1933 West Mall 9:00-10:30a.m. Ernie Manes - Equationally definable full subcategories of spaces. 10:30-11:00a.m. Break 11:00-12:30p.m. Vaughan Pratt - Axiomatizing affine and Euclidean space. 12:30-2:30p.m. Lunch 2:30-4:00p.m. Pieter Hofstra - Types, groupoids and homotopy. 4:00-4:30p.m. Break 4:30-5:30p.m. Dorette Pronk - The left and right adjoints of Span. Saturday, May 30, 2009 Research talks - WMAX 240 - 1933 West Mall 9:00-9:50a.m. Mehrnoosh Sadrzadeh - What is the vector space content of what we say? A compact categorical approach to distributed meaning. 9:50-10:30a.m. Robert Seely - The basics of Cartesian differential restriction categories. 10:30-11:00a.m. Break 11:00-12:00 Michael Johnson - Monadicity, descent, and classical database view updating. 12:00-12:30p.m. Art Stone - What might Counter-bi-algebras be? 12:30-2:00p.m. Lunch 2:00-2:40p.m. Robin Cockett - Cartesian differential restriction categories. 2:40-3:05p.m. Brian Redmond - TBA 3:05-3:40p.m. Shusaku Tsumoto - Medical data mining. 3:40-4:10p.m. Break 4:10-4:35p.m. Brett Giles - Reversible computation and Frobenius algebras. 4:35-5:00p.m. Aaron Hunter - Algebraic considerations on the dynamics of belief. 6:00p.m. Banquet - Cedar Room in the Ponderosa Building Sunday, May 31, 2005 Sunday talks will be in WMAX 240 - 1933 West Mall 9:00- 9:50a.m. Bob Rosebrugh - EASIK: Database design and manipulation implemented categorically. 9:50-10:20a.m. Sean Nichols - On strong reduction in combinatory logic. 10:20-11:00a.m. Break 11:00-12:00 Vaughan Pratt - Euclid's postulates at all dimensions. The following paragraphs repeat the information from the first announcement. The Department of Mathematics at the University of British Columbia in cooperation with the Pacific Institute of Mathematical Sciences is hosting the Foundational Methods in Computer Science workshop on May 28th - 31st, 2009, on the University of British Columbia Campus in Vancouver, Canada The workshop is an annual informal meeting intended to bring together researchers in mathematics and computer science. There is a focus on the application of category theory in computer science. However, all those who are interested in category theory or computer science are welcome to attend. The meeting begins with a reception at 6pm in the Ruth Blair room in Walter Gage Towers on the UBC campus on Thursday May 28, 2009. The scientific program starts on May 29, and consists of a day of tutorials aimed at students and newcomers to category theory, as well as a day and a half of research talks. The meeting ends at mid-day on May 31. Research talks There will be some invited presentations, but the majority of the talks are solicited from the participants. If you wish to give a talk please send a title and abstract to johnm@math.ubc.ca. Time slots are limited, so please register early if you would like to be considered for a talk. Graduate student participation is particularly encouraged at FMCS. Registration details will appear in the next announcement. Previous meetings Previous FMCS meetings were held in Pullman (1992), Portland (1993), Vancouver (1994), Kananaskis (1995), Pullman (1996), Portland (1998), Kananaskis (1999), Vancouver (2000), Spokane (2001), Hamilton (2002), Ottawa (2003), Kananaskis (2004), Vancouver (2005), Kananaskis (2006), Hamilton (2007), and Halifax (2008). Organizing committee: Robin Cockett (Calgary) John MacDonald (UBC) Phil Mulry (Colgate) Peter Selinger (Dalhousie) Local Organizer: John MacDonald (UBC) [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Wed May 27 11:00:35 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 27 May 2009 11:00:35 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9Jev-0004Rc-Si for categories-list@mta.ca; Wed, 27 May 2009 10:59:09 -0300 Date: Tue, 26 May 2009 19:53:32 -0700 Subject: categories: Re: patenting colimits? From: David Spivak To: categories@mta.ca Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: David Spivak Message-Id: Status: RO X-Status: X-Keywords: X-UID: 75 One reason a mathematician may want to patent a practical use of his idea is because if he doesn't do so, someone else can. If some corporation spent the money to understand a mathematical construction and then patented its application, not only does that corporation stand to make a lot of money (on a construction the corporation was hardly involved with), it can also keep competitors from using the ideas. Or, the corporation can "bury it," by patenting the ideas and then not using them, but still using litigation to prevent others from putting the ideas to good use. Once you patent, you control the rights to the intellectual property, and can make the product more or less widely available. To me, the patenting of an application of category theory is not an issue; the problem would be if someone patented such an application of category theory and then restricted its use or attempted to make undue amounts of money from it. [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Wed May 27 11:00:53 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 27 May 2009 11:00:53 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9JgY-0004b9-Ou for categories-list@mta.ca; Wed, 27 May 2009 11:00:50 -0300 Date: Tue, 26 May 2009 23:29:15 -0400 Subject: categories: Re: patenting colimits? From: Zinovy Diskin To: Dusko Pavlovic , categories@mta.ca Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Zinovy Diskin Message-Id: Status: O X-Status: X-Keywords: X-UID: 76 Interestingly, software industry is heading in the opposite -- patent-free -- direction. It's called Open source software development, and it is tremendously popular. There are several impressive examples, such as the extremely successful Eclipse project http://www.eclipse.org, (btw, Eclipse is partly based on categorical ideas that engineers developed/reinvented from scratch). Another example is the use of open source software for commercial products by such giants as IBM. (Of course, building legal foundations for this is a separate story but somehow they managed it.) I have a feeling (though i maybe wrong), that patenting is becoming an outdated enterprise in the internet era. Z. [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Wed May 27 11:01:48 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 27 May 2009 11:01:48 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9JhQ-0004hE-QK for categories-list@mta.ca; Wed, 27 May 2009 11:01:44 -0300 Date: Wed, 27 May 2009 08:21:45 +0200 (CEST) Subject: categories: Re: patenting colimits? From: soloviev@irit.fr To: "Eduardo J. Dubuc" , categories@mta.ca Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: soloviev@irit.fr Message-Id: Status: O X-Status: X-Keywords: X-UID: 77 Aha, and then you'll apply for a position and someone will say that you violated a patent when you use colimits in your work. Best - S. Soloviev > if they want to patent, let them patent !! > > [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Wed May 27 11:02:36 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 27 May 2009 11:02:36 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9JiD-0004nW-CX for categories-list@mta.ca; Wed, 27 May 2009 11:02:33 -0300 Date: Wed, 27 May 2009 09:28:53 +0200 From: David CHEMOUIL To: categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: David CHEMOUIL Message-Id: Status: RO X-Status: X-Keywords: X-UID: 78 Hello, On Tue, 26 May 2009 05:46:09 +0100 (BST), Dusko Pavlovic wrote: > *but* if you write a book, and present pythagora's theorem in it, you will > not only be able to copyright it, but it will actually be almost > impossible for you to distribute your book without copyright it, and > without selling the copyright to a publisher. so anyone who wants to use > your version of pythagoras' theorem has to ask your publisher's > permission. More precisely, AFAIK, copyright effectively applies to the *form* that you used to describe Pythagora's theorem. As such, no one is allowed to reprodu= ce it with the same exact form as you long as the copyright holder doesn't gra= nt him or her that exclusive right. > patents are crazier than copyright --- but maybe not that much crazier. > you cannot patent mathematics, but you can patent "method and apparatus" > for a particular application of pythagoras' theorem. (they always call it > "method and apparatus".) you cannot patent modular exponentiation, nor the > conjecture that inverting it (ie computing the discrete logarithms) is > computationally unfeasible. but you can patent a method and apparatus to > share a public key by exchanging and multiplying two modular exponents. > the essence of your originality argument will rely upon the novel use of > the conjecture that the discrete logarithms are hard to compute, on which > the security of your system is based. Let us however recall that patenting algorithms is possible in the USA or in Japan but certainly not in the EU, until now (despite much repeated lobbying from pharmaceutical and IT companies). Still, the European Patent Office (EPO) has already accepted tens of thousands of such patents, by cheating with the law (indeed, the law says that you can't patent an algorithm "as such", which the EPO interpreted as : you can patent an algorithm as long as it is part of a "technical mechanism" such as an MP3 player, for instance). Without even entering into social or economic outcome of "openness" of results, or so-called innovations (see Maskin's publications for more information, for instance), I'd like to point out an ethical issue here. Th= at is the harm done to a 500-year, or so, social contract between scientists acknowledging publicly, that is in publications, that they stand on the shoulders of giants or, with less grandiosity, on other colleagues' results= .=20 Of course, there is a strong incentive, to say the least, in many instituti= ons for the "valorisation" of results. My point is that a strong "openness" (su= ch as publications under "creative commons" or release of software under free/open-source licences) may give a far better valorisation of results th= an strong, defensive, appropriation, while being more compliant to centuries of scientific practice.=20 Best regards, dc --=20 David CHEMOUIL ONERA/DTIM - 2 avenue =C3=89douard Belin - F-31055 Toulouse Tel: +33 (0) 5 6225 2936 - Fax: +33 (0) 5 6225 2593 http://www.onera.fr/staff/david-chemouil [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Wed May 27 11:03:29 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 27 May 2009 11:03:29 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9Jj3-0004uz-DX for categories-list@mta.ca; Wed, 27 May 2009 11:03:25 -0300 Date: Wed, 27 May 2009 13:29:50 +0200 Subject: categories: Re: patenting colimits? From: zoran skoda To: Greg Meredith , categories@mta.ca Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: zoran skoda Message-Id: Status: RO X-Status: X-Keywords: X-UID: 79 American patent laws are radically different and more backwards in common sense than ones say in India. In India you can patent only a process/means how to do certain thing, not a thing itself, what is more natural, and this is a main dispute between american industry and various movements in India. For example, once there is a nuclear energy, one can use it for any thing which requires energy. But in american law it is theoretically possible that in times when there was not a single nuclear submarine, one registers a patent for the idea/concept nuclear submarine without any specific techincal details on construction. Similarly for the concept of a shoe which charges battery by using the energy disssipated in changing pressure on the shoe when walking. In Indian patent law, any specific way to achieve that is patentable. But somebody else who wishes to independently makes another design achieving the same function can not be prevented by that patent. Also in Indian patent law one can not patent existing natural resources, like species of wild plants, naturally existing compounds in plants na rocks and alike; and my understanding is that this hence applies to mathematical facts like number 13 is prime even if before unknown to the mankind. Zoran [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Wed May 27 11:04:12 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Wed, 27 May 2009 11:04:12 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9Jjk-00050m-Js for categories-list@mta.ca; Wed, 27 May 2009 11:04:08 -0300 Date: Wed, 27 May 2009 14:40:40 +0200 From: fibonchi@di.unipi.it Subject: categories: ICE09: LAST CALL FOR PAPERS Content-Type: text/plain; charset=ISO-8859-1 To: undisclosed-recipients:; Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: fibonchi@di.unipi.it Message-Id: Status: RO X-Status: X-Keywords: X-UID: 80 2nd Interaction and Concurrency Experience (ICE'09) Structured Interactions Satellite workshop of CONCUR 2009 31st of August 2009 Bologna, Italy Homepage: http://ice09.dimi.uniud.it/ -- Invited Speakers -- - Farhad Arbab (CWI) - Doron Peled (Bar Ilan University) Interaction and Concurrency Experiences (ICEs) is intended as a series of international scientific meetings oriented to researchers in various fields of theoretical computer science. The timeliness and novelty of these events relies both on the variety of the topics that will be treated on each event and on the adopted paper selection mechanism. Every experience will focus on a different specific topic which affects several areas of computer science. A thorough scientific debate among PC and authors of submitted papers will parallel the reviewing process. After the paper selection phase, papers will be published on the web and the discussion will be extended to perspective participants. -- Scope of ICE'09 -- The general scope is to include theoretical and applied aspects of interactions and the synchronization mechanisms used among actors of concurrent/distributed systems. The workshop intends to attract researchers interested in models, verification, tools, and programming primitives concerning such structured interactions. The theme of ICE09 will be structured interactions by which we mean the class of synchronisations that go beyond the "simple" point-to-point synchronisations. A few examples of such structured interactions are: multicast or broadcast synchronisations, even-notification based interactions, time dependent interactions, distributed transactions, stateless/statefull interactions. Not only structured interactions have been studied "in isolation", but researchers have also considered mutual relations and theoretical frameworks featuring uniform representations and/or co-existence of different structured interactions. As a matter of fact, different structured interactions are typically required when specifying views of a distributed system or when considering it at different levels of abstraction. For instance, multicast or broadcast interactions (desirable at a high level of abstraction) have to be mapped on more basic kind of interactions like point-to-point asynchronous synchronisations. The interest in such interactions is growing due to the recent trend in providing abstractions that allow one to master the complexity of distributed systems. Remarkable research lines in this area are the use of types or behavioural equivalences to guarantee properties of concurrent/distributed systems (eg., progress properties) or the use of model-driven approaches in order to achieve correctness "by construction" (eg., graceful termination), or else the relations among interactions, mobility and spatial aspects (eg., bigraphs). -- Topics -- Topics of interest include, but shall not be limited to: - models, logic and types for structured interactions; - expressiveness results; - timed and hybrid interactions; - verification, analysis and tools; - programming primitives for structured interactions; - structured interactions as coordination mechanisms; - structured interactions inspired by emerging computational models (systems biology, quantum computing, etc.). -- Selection Procedure -- The workshop proposes an innovative paper selection mechanism based on an interactive discussion amongst authors and PC members. As shown by the past edition of ICE, this considerably improves the quality of the papers, the reviews and the discussion during the workshop. We continue by detailing the selection procedure. After the submission deadline expires, each PC member selects a number of suitable papers to review before the start of the discussion phase. At the beginning of the discussion, each submitted paper is published on a Wiki and associated with a discussion forum whose access will be restricted to the authors and to all the PC members. The latter will be able to post comments/questions which the authors will reply to (authors will obviously have access only to forums associated with their own papers). Thus, the discussion on forums (and hence the reviewing process of papers) may be enhanced by the additional comments of interested PC members. -- The Public Wiki -- After the notification, the accepted papers will be published on a public forum, the rationale being to initiate public discussions that will trigger and stimulate the scientific debate of the workshop. We argue that this will drive the workshop discussions and let perspective participants to interact with each other well in advance with respect to the modus operandi of more traditional events. -- Submission Guidelines -- Papers must report previously unpublished work and not be submitted to another conference/workshops with refereed proceedings. Programme Committee members, barring the co-chairs, may (and indeed are encouraged) to contribute. Accepted papers must be presented at the workshop by one of the authors. There is no specific page limit, but authors should strive for brevity. Details of the submission mechanism will follow in due course. -- Dissemination -- The ICE09 post-proceeding will be published in a novel series: Electronic Proceedings in Theoretical Computer Science. -- Important Dates -- - Abstract submission: 29 May 2009 - Submission deadline: 5 June 2009 - Reviews due: 26 June 2009 - Discussion: from 29 June to 11 July 2009 - Notification to authors: 13 July 2009 - Workshop: 31 August 2009 -- Program Committee -- * Simon Bliudze (CEA LIST, France) * Eduardo Bonelli (LIFIA, University of LaPlata, Argentina) * Andrea Bracciali (University of Pisa, Italy) * Roberto Bruni (University of Pisa, Italy) * Marco Carbone (IT University of Copenhagen, Denmark) * Bob Coecke (Oxford University, UK) * Vincent Danos (University of Edinburgh, UK) * Erik de Vink (Technische Universiteit Eindhoven) * Georgios Fainekos (NEC Laboratories, USA) * Goran Frehse (Universite Joseph Fourier Grenoble 1 - Verimag,France) * Carlo A. Furia (ETH Zuerich, Switzerland) * Fabio Gadducci (University of Pisa, Italy) * Ichiro Hasuo (Kyoto University, Japan) * Thomas Hildebrandt (IT University of Copenhagen, Denmark) * Daniel Hirschkoff (ENS, Lyon, France) * Barbara Koenig (University of Duisburg-Essen, Germany) * Ivan Lanese (University of Bologna, Italy) * Hernan Melgratti (Universidad de Buenos Aires, Argentina) * Dimitris Mostrous (Imperial College, London, UK) * Madhavan Mukund (Chennai mathematical Institute, India) * Dejan Nickovic (EPFL Lausanne, Switzerland) * Ana Sokolova (University of Salzburg, Austria) * Hugo Torres Vieira (New University of Lisbon, Portugal) * Angelo Troina (University of Torino, Italy) * Nobuko Yoshida (Imperial College, London, UK) * Herbert Wiklicky (Imperial College, London, UK) -- ICEcreamers -- - Filippo Bonchi (CWI) - Davide Grohmann (Universita' di Udine) - Paola Spoletini (Politecnico di Milano) - Emilio Tuosto (University of Leicester) ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program. [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 00:28:01 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 00:28:01 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9WGz-0000tB-QS for categories-list@mta.ca; Thu, 28 May 2009 00:27:17 -0300 Date: Wed, 27 May 2009 10:18:27 -0600 (MDT) Subject: categories: Re: patenting colimits? From: mjhealy@ece.unm.edu To: "Michael Barr" , categories@mta.ca Content-Type: text/plain;charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: mjhealy@ece.unm.edu Message-Id: Status: O X-Status: X-Keywords: X-UID: 81 Dear Michael and all, I am unaware of a great deal of the history of category theory in grant funding. The NSF declaration is troubling, especially since my colleague= s and I so far have had our category-theoretic proposals in cognitive neuroscience rejected. Some of the reviewers, though, did seem to find favor with our use of category theory in relation to their subject; the problem seems to have been more in other areas. We haven't given up! I regret not joining the FMCS crowd at UBC. Too much work has resulted from a prior commitment. Best regards, Mike > Interesting comments by Vaughan. I have not looked at this patent and > have no intention of doing so. But Charles and I, both in CTCS and in = a > paper published in some CS conference proceedings exhibited things like > a sketch for trees of integers as a pushout or amalgamated sum of a ske= tch > for trees and that for integers by identifying the sort for integers in > the latter with the sort for leaves in the fomer. I think we have a > triple amalgamation too, something like trees of lists of integers. So > evidence of prior art certainly exists, if anyone cares. > > On the other hand, I for one would welcome serious applications of > category theory in industry. My former department is hiring in only th= ree > areas: number theory (in which they are truly strong), applied math, an= d > statistics (in each of which I rather suspect they are truly weak since > they are competing with every g-d university in North America). I woul= d > just love to shove it in their collective faces that by allowing the > category theory group to wither, they have allowed an important applied > area to disappear. But no, they would rather be in the rearguard than = the > advanced guard. > > Wouldn't it be nice to make the same point to NSF which announced > officially in 1993 that there would never again be any funding in categ= ory > theory? > > Michael > > > [For admin and other information see: http://www.mta.ca/~cat-dist/ ] > [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 00:28:01 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 00:28:01 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9WFM-0000qZ-Rq for categories-list@mta.ca; Thu, 28 May 2009 00:25:36 -0300 Date: Wed, 27 May 2009 17:08:29 +0100 From: Steve Vickers To: Toby Bartels , categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Steve Vickers Message-Id: Status: O X-Status: X-Keywords: X-UID: 82 Toby Bartels wrote: > ... > Certainly much of what is in the patent application is obvious, > but perhaps not all of it; were these diagrams of diagrams a new idea?, > or was applying them to computer system specifications a new idea?. > ... Dear Toby, The idea of treating specifications as colimits is a few decades old now. Burstall and Goguen used it in their categorical account of their specification language Clear, with a specification used to construct a new theory as colimit of others. The hierarchical step, diagrams of diagrams, was studied by Catherine Oriat in her thesis and (I believe) a TCS paper in 2000. My own student Gillian Hill investigated a variant of this (PhD Thesis 2002; also two papers with me, 2001, 2006), replacing the category of finite diagrams over a base category C by the equivalent category of finitely presented presheaves. Both are finite cocompletions, but a presheaf presentation by generators and relations comes over neatly as a "configuration by components and sharing". For obvious reasons the iterated construction "flattens" back down to the single one (the construction is a KZ-monad in the 2-category of categories). Gillian also investigated a multi-level configuration language that maintains the hierarchical structure without flattening (configurations of configurations of configurations of ...) and includes cross-level specification morphisms. However, we did not persevere to work out the categorical semantics of this, nor did we make a computer implementation. Regards, Steve Vickers. [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 00:28:01 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 00:28:01 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9WGI-0000rt-Cj for categories-list@mta.ca; Thu, 28 May 2009 00:26:34 -0300 Date: Wed, 27 May 2009 18:12:00 +0200 From: David CHEMOUIL To: David Spivak , categories@mta.ca Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Sender: categories@mta.ca Precedence: bulk Reply-To: David CHEMOUIL Message-Id: Status: O X-Status: X-Keywords: X-UID: 83 On Tue, 26 May 2009 19:53:32 -0700, David Spivak wrote: > One reason a mathematician may want to patent a practical use of his idea= is > because if he doesn't do so, someone else can. If some corporation spent > the money to understand a mathematical construction and then patented its > application, not only does that corporation stand to make a lot of money = (on > a construction the corporation was hardly involved with), it can also keep > competitors from using the ideas. Or, the corporation can "bury it," by > patenting the ideas and then not using them, but still using litigation to > prevent others from putting the ideas to good use. First, patent laws are national laws. But it is generally acknowledged, even in the most patent-friendly countries, that a patent should protect somethi= ng *original*. As long as you have published your idea with a clearly identifiable date of publication, for instance in a scientific journal, no one should be able to patent it afterwards (I write "should" because patent offices are often a bit skimpy). Secondly, and once again, many countries do not allow patenting mathematical results. Things are less clear for algorithms. > Once you patent, you control the rights to the intellectual property, and > can make the product more or less widely available. To me, the patenting= of > an application of category theory is not an issue; the problem would be if > someone patented such an application of category theory and then restrict= ed > its use or attempted to make undue amounts of money from it. As a matter of fact, considering the cost of patent registration, the depositer must expect something... Either to earn money, or to have its competitors lose money, or (that may be the case for many public institutio= ns) to give evidence for "valorisation" of results to public authorities.=20 Except for the last case where patents may, perhaps, not be used to prevent scientific work, other applications of patents are likely to be problematic both ethically and economically as far as scientific research is concerned (think about scientists working in institutions unable to afford royalties = or attorney expenses).=20 dc --=20 David CHEMOUIL ONERA/DTIM - 2 avenue =C3=89douard Belin - F-31055 Toulouse Tel: +33 (0) 5 6225 2936 - Fax: +33 (0) 5 6225 2593 http://www.onera.fr/staff/david-chemouil [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 00:28:19 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 00:28:19 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9WHw-0000vQ-42 for categories-list@mta.ca; Thu, 28 May 2009 00:28:16 -0300 Date: Wed, 27 May 2009 12:22:28 -0700 From: Toby Bartels To: categories@mta.ca, zoran skoda Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: Toby Bartels Message-Id: Status: O X-Status: X-Keywords: X-UID: 84 zoran skoda wrote in part: >But in american law it is theoretically possible that in times when there >was not a single nuclear submarine, one registers a patent >for the idea/concept nuclear submarine without >any specific techincal details on construction. This is a good example, since if you read Feynman's account of how he didn't get the patent for that (but did for other things), you can see how the ideas that he got patents for really *were* "obvious at the time the invention was made to a person having ordinary skill in the art to which said subject matter pertains" (to quote current law, which may have been different in 1945). But of course, the patent office had no way of knowing that. Here's an abbreviated account: http://ipho2008.hnue.edu.vn/LinkClick.aspx?fileticket=uwXCnR4Vj4E%3D&tabid=97&mid=723 --Toby [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 00:29:07 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 00:29:07 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9WIh-0000yf-RT for categories-list@mta.ca; Thu, 28 May 2009 00:29:03 -0300 Date: Wed, 27 May 2009 12:33:44 -0700 From: Toby Bartels To: categories@mta.ca, Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: Toby Bartels Message-Id: Status: O X-Status: X-Keywords: X-UID: 85 Dusko Pavlovic wrote in part: >i don't think that we published anything about this construction. the >patent description was written by the lawyer (a very bright woman, i think >with an MIT PhD, who now runs the world for google). some other things >that we didn't publish were perhaps closer to a mathematical result. but >the purpose of it all was to build software, not to publish mathematical >results. It's a shame if there were new mathematical results (perhaps, pace Steve Vickers's post, there weren't) that were published only in a patent application. Maybe they were too obvious to be worthy of publication, but then weren't they too obvious to be worthy of a patent? Of course, you were presumably doing work for hire, and I'm not trying to blame you for all of this, but I'm happy when people get outraged about these practices. While I'm here, some clarifications are my previous posts: When I first wrote "I'm not sure that it's anything new", I didn't mean the novelty of the invention in the patent but instead the practice of patenting such things. And when I wrote "I would not wanted to be hobbled by a patent on the relevant mathematics", of course I meant a patent on implementing the relevant mathematics in software. --Toby [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 00:29:38 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 00:29:38 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9WJC-00011K-Q1 for categories-list@mta.ca; Thu, 28 May 2009 00:29:34 -0300 Date: Wed, 27 May 2009 23:09:24 +0100 (BST) From: Bob Coecke To: categories@mta.ca Subject: categories: Tutorial: Categories for the practicing physicist MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Bob Coecke Message-Id: Status: O X-Status: X-Keywords: X-UID: 86 We have put a tutorial on symmetric monoidal categories on the arXiv: http://arxiv.org/abs/0905.3010 Categories for the practising physicist (104 pages) Bob Coecke and Eric Oliver Paquette It is directed to physicists who unlike mathematical physicists, do not have a strong background in pure maths. The target audience are researchers in quantum foundations and quantum infomation. The main goal is to show that monoidal categories are a natural starting point to craft theories of physics, and that they are closely related to something physicists are very used to, namely Dirac notation. Some effort is made to unpack the definition of a symmetric monoidal category which given its `size', is just too much to grasp at once. On the other hand, there is a very clear physical intuition to monoidal categories which can be easily grasped by physicists or any other operational scientist. This tutorial starts from this operational intuition and gradually converts it on mathematical substance. As a consequence, the attempt to convey a story is more prominent than mathematical rigor. In our interaction with quantum foundationalists and quantum informaticians we noticed a great need for a tutorial of this nature. [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 21:55:04 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 21:55:04 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9qLg-000313-EN for categories-list@mta.ca; Thu, 28 May 2009 21:53:28 -0300 From: "David Espinosa" To: "Categories" Subject: categories: Re: patenting colimits? Date: Thu, 28 May 2009 00:15:41 -0700 MIME-Version: 1.0 Content-Type: text/plain;format=flowed; charset="iso-8859-1";reply-type=original Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: "David Espinosa" Message-Id: Status: O X-Status: X-Keywords: X-UID: 88 We seem to be more excited about patents than categories! I guess opinions are cheaper than theorems... I'd say that citation is the academic form of currency. Here's a dictionary: Academia: Academics rush to publish before their colleagues. Industry: Companies rush to patent before their competition. Academia: Academics get quite upset if you use their ideas without citing them. Industry: Companies sue you if you use their patents without paying them. Academia: A generous academic lets you publish his idea (yeah, right). Industry: A generous businessman lets you profit from his idea (yeah, right). Academia: You can publish improvements to someone's basic idea. Industry: You can patent improvements to someone's basic idea. So you can see why I find the academic "high horse" attitude towards patents a bit hypocritical. BTW, here's a difference between academia and industry, which comes about because money is more flexible than time: Academia: An academic *cannot* give you any credit for his existing publication. Industry: A company *can* let you profit from its existing patent. David [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 21:56:31 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 21:56:31 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9qOZ-0003An-Fe for categories-list@mta.ca; Thu, 28 May 2009 21:56:27 -0300 Date: Thu, 28 May 2009 17:49:40 +0200 From: Uwe.Wolter@ii.uib.no To: Steve Vickers , categories@mta.ca Subject: categories: Re: patenting colimits? MIME-Version: 1.0 Content-Type: text/plain;charset=ISO-8859-1;DelSp="Yes";format="flowed" Content-Disposition: inline Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Uwe.Wolter@ii.uib.no Message-Id: Status: O X-Status: X-Keywords: X-UID: 89 Quoting Steve Vickers : > Toby Bartels wrote: >> ... >> Certainly much of what is in the patent application is obvious, >> but perhaps not all of it; were these diagrams of diagrams a new idea?, >> or was applying them to computer system specifications a new idea?. >> ... > > Dear Toby, > > The idea of treating specifications as colimits is a few decades old > now. Burstall and Goguen used it in their categorical account of their > specification language Clear, with a specification used to construct a > new theory as colimit of others. Yes, Steve! And they coined also the idea of so-called "based objects" that allow to distinguish between parameter specifications and imported specifications once you are going to develop a fully fledged theory of parametrized specifications. Ingo Classen worked out this in more detail in his PhD thesis around 1995 (?) at Technical University Berlin. Best regards Uwe Wolter [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Thu May 28 21:57:53 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Thu, 28 May 2009 21:57:53 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1M9qPt-0003GG-MZ for categories-list@mta.ca; Thu, 28 May 2009 21:57:49 -0300 Date: Thu, 28 May 2009 22:07:58 +0100 (BST) From: Dusko Pavlovic To: Toby Bartels , categories@mta.ca Subject: categories: Re: patenting colimits? MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Dusko Pavlovic Message-Id: Status: O X-Status: X-Keywords: X-UID: 90 On Wed, 27 May 2009, Toby Bartels wrote: >> i don't think that we published anything about this construction. the >> patent description was written by the lawyer (a very bright woman, i think >> with an MIT PhD, who now runs the world for google). some other things >> that we didn't publish were perhaps closer to a mathematical result. but >> the purpose of it all was to build software, not to publish mathematical >> results. > > It's a shame if there were new mathematical results > (perhaps, pace Steve Vickers's post, there weren't) > that were published only in a patent application. is publishing really the supreme purpose of mathematical results? it is the main method to get an academic job, but academia itself is not a purpose of itself. mathematics and sciences are a good thing in at least two ways: 1) as a form of communication (collaboration) between people, and 2) as a source of benefits (better life, useful technologies) the imperative of publishing evolved as a part of (1). are the current publishing practices still serving their original purpose, to help collaboration? or did we put the cart in front of the horse? does the publishing scrutiny really improve sciences? (search, web, internet all arose from largely unpublished results. some great ideas of category theory did not hurry to get published. and the other way around...) patenting evolved as a part of (2). it also deviated from its original purpose, and now mostly hampers social benefits... can such problems be solved on moral grounds, by saying "patenting is bad, i won't patent"? some people think it can. both grothendieck and newton said "publishing is bad, i won't publish". and did anything change? i somehow don't think that it would change if i joined them. better methods to solve these problems are sought than abstinence and moralizing. re > It's a shame if there were new mathematical results > (perhaps, pace Steve Vickers's post, there weren't) i didn't think that they were research level mathematical results. so i am impressed that steve vickers enumerates so many publications about them. in any case, even our tool implementing these results predates the publications that steve vickers mentions. > Maybe they were too obvious to be worthy of publication, > but then weren't they too obvious to be worthy of a patent? you seem to have missed the main point of my previous post. i described one of the most important patents in computing: the diffie hellman key exchange. its mathematical content boils down to the conjecture that discrete logarithms are computationally hard. this mathematical content has been obvious to nearly anyone who tried to compute discrete logarithms. the point is that ** the novelty of a patent is not in the underlying math. (by law, mathematics cannot be patented.) ** the novelty of a patent is in the "method and apparatus" extracted from it. (the intent of a patent is not to protect knowledge, but an application, a new way to use it.) (gotta run) -- dusko [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon Jun 1 12:44:20 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 01 Jun 2009 12:44:20 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1MB9dj-0003kM-31 for categories-list@mta.ca; Mon, 01 Jun 2009 12:41:31 -0300 Date: Thu, 28 May 2009 18:24:13 -0700 From: Toby Bartels To: David Espinosa , Subject: categories: Re: patenting colimits? Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: categories@mta.ca Precedence: bulk Reply-To: Toby Bartels Message-Id: Status: RO X-Status: A X-Keywords: X-UID: 91 David Espinosa wrote in part: >We seem to be more excited about patents than categories! I guess opinions >are cheaper than theorems... Of course; it's a matter of convenience, not excitement. >I'd say that citation is the academic form of currency. Here's a >dictionary: >Academia: Academics get quite upset if you use their ideas without citing >them. >Industry: Companies sue you if you use their patents without paying them. >Academia: You can publish improvements to someone's basic idea. >Industry: You can patent improvements to someone's basic idea. Here's what you missed: Academia: Academics can freely use ideas if they cite them, and nobody minds if they come up with idea independently. Industry: Companies must pay to use patented ideas, even if they come up with the idea indpendently, at whatever rate (possibly prohibitive) set by the owner of the patent. --Toby [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon Jun 1 12:45:04 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 01 Jun 2009 12:45:04 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1MB9h5-00044G-35 for categories-list@mta.ca; Mon, 01 Jun 2009 12:44:59 -0300 From: Dusko Pavlovic To: Zinovy Diskin , Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Subject: categories: Re: patenting colimits? Date: Fri, 29 May 2009 12:57:19 -0700 Sender: categories@mta.ca Precedence: bulk Reply-To: Dusko Pavlovic Message-Id: Status: O X-Status: X-Keywords: X-UID: 92 [sorry, i just noticed this] On May 26, 2009, at 8:29 PM, Zinovy Diskin wrote: > impressive examples, such as the extremely successful Eclipse project > http://www.eclipse.org, (btw, Eclipse is partly based on categorical > ideas that engineers developed/reinvented from scratch). i designed two tools which people who built them built on top of eclipse, and i must admint that i managed to completely miss those categorical ideas. eclipse is very handy, but some simple class hierarchies often become unrecognizable in its straitjacket. i am probably not the only one who would be curious to learn more about category theory behind eclipse :) > Another > example is the use of open source software for commercial products by > such giants as IBM. i hope that you are right that it is a good thing that IBM supports the open source. i also hope that it is a good thing that Exxon, Chevron and BP support the alternative sources of energy, and that Philip Morris supports the teen culture. -- dusko [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon Jun 1 12:47:07 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 01 Jun 2009 12:47:07 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1MB9j3-0004GD-9q for categories-list@mta.ca; Mon, 01 Jun 2009 12:47:01 -0300 MIME-Version: 1.0 Date: Sat, 30 May 2009 08:07:22 -0400 Subject: categories: Re: patenting colimits? From: Zinovy Diskin To: Dusko Pavlovic , Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: categories@mta.ca Precedence: bulk Reply-To: Zinovy Diskin Message-Id: Status: O X-Status: X-Keywords: X-UID: 93 On Fri, May 29, 2009 at 3:57 PM, Dusko Pavlovic wrote: > i designed two tools which people who built them built on top of eclipse, > and i must admint that i managed to completely miss those categorical ideas. > eclipse is very handy, but some simple class hierarchies often become > unrecognizable in its straitjacket. i am probably not the only one who would > be curious to learn more about category theory behind eclipse :) > well, I've overstated it a little bit because of the context. What I actually meant was Eclipse Modeling Framework (EMF) -- one of the several top-level projects constituting Eclipse. The core idea of EMF is that a majority of complex structures called models can be presented as lax functors m: EC --> mRel, where EC is the category freely generated by some graph EM called the Ecore metamodel, and mRel is bicategory of finite sets and finite multirelations (spans) between them. However, not every such functor is a valid model because the metamodel EM is actually a sketch, EC is the theory generated by EM and m should be a functor preserving the structure (using Makkai's rather than classical sketches is much more technically convenient here). Models are used for code generation, and code is just another model. For example, a Java program is a morphism p: JC-->mRel with JC being the theory generated by the Java metamodel sketch JM. So, code generation would be a case of the change of base situation if we had a theory morphism e2j: JC-->EC (generated by a Kleilsi arrow JM-->EC). The real situation is much more complicated because e2j is a span EC <-- o --> JC rather than a functor. This is a rough picture. Metamodels and models appearing in practice are big, and therefore are designed and stored in fragments called packages. Gathering them together (virtually via the so called package merge) is an operation based on taking colimits of the diagram specifying package relationships. Code generation/change of base in the presence of packages gives rise to sheaves. And so on. Of course I did not mean that Eclipse developers explicitly used categorical ideas. Relations between software systems like Eclipse and cat. theory are like relations between physical phenomena and their mathematical models. Z. >> Another >> example is the use of open source software for commercial products by >> such giants as IBM. > > i hope that you are right that it is a good thing that IBM supports the open > source. i also hope that it is a good thing that Exxon, Chevron and BP > support the alternative sources of energy, and that Philip Morris supports > the teen culture. > > -- dusko > although a part of Eclipse but an important one. Here is what the EMF Book [1] says (pages 4-5): << The development work in Eclipse is divided into several top-level projects, including the Eclipse Project, the Modeling Project, the Tool Project, and the Technology project. .... The Eclipse Modeling Project is the focal point for the evolution and promotion of model-based development technologies at Eclipse. At its core is EMF, which provides the basic framework for modeling. Other modeling sub-projects build on top of the EMF core, providing such capabilities as model transformation, database integration, and graphical editor generation... [For admin and other information see: http://www.mta.ca/~cat-dist/ ] From rrosebru@mta.ca Mon Jun 1 12:47:43 2009 -0300 Return-path: Envelope-to: categories-list@mta.ca Delivery-date: Mon, 01 Jun 2009 12:47:43 -0300 Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1MB9ja-0004Ko-UV for categories-list@mta.ca; Mon, 01 Jun 2009 12:47:34 -0300 Date: Sun, 31 May 2009 12:57:19 +0200 (CEST) From: Paul-Andre Mellies To: categories@mta.ca Subject: categories: postdoc position in Paris MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Sender: categories@mta.ca Precedence: bulk Reply-To: Paul-Andre Mellies Message-Id: Status: O X-Status: X-Keywords: X-UID: 94 Dear colleagues, The deadline for application to the postdoctoral position in our laboratory PPS (University Paris Diderot) has been postponed to June the 15th. The announcement follows. Paul-Andre ====================================================== Postdoctoral position in PPS (CNRS & University Paris 7) Curry-Howard and Concurrency Theory ====================================================== A 12-month postdoctoral position is available within the Laboratory PPS (Preuves Programmes Systemes) located at University Paris 7 Denis Diderot: http://www.pps.jussieu.fr/ The position is supported by the research project Curry-Howard and Concurrency Theory (CHOCO) funded by the French national research agency ANR. http://choco.pps.jussieu.fr/ Important dates: - deadline for application: June 15th 2009 - notification: June 29th 2009 - suggested starting date: September 1st 2009 Application procedure. Full application should be sent before May 31st 2009 including a resume, a short research project (1 page) and two names of possible references. This should be preferably done by email or at the postal address below. For all correspondance use the contact addresses: postdoc-choco@pps.jussieu.fr Paul-Andre Mellies Laboratoire PPS Universite Paris 7 - Denis Diderot Case 7014 75205 Paris Cedex 13 FRANCE The net salary will be around 2000 euro/month before income tax. The starting date for the postdoctoral position is September 2009 although later dates may be also considered. Description The general purpose of the project CHOCO is to investigate the syntactic, semantic and algebraic aspects of proof theory in order to integrate concurrency theory in the Curry-Howard correspondence between proofs and programs. The interdisciplinary nature of the project between proof theory and concurrency theory means that candidates from various scientific horizons are welcome to apply. On the other hand, we will consider with special interest applications by candidates with background in one or several of the fields: - linear logic (proof nets, geometry of interaction) - semantics (game semantics, vectorial semantics) - concurrency theory (process calculi, presheaf semantics) - type theory (realizability, types for process calculi) - rewriting theory (lambda-calculus, diagrammatic rewriting) - category theory (categorical algebra, topos theory) The applicant should hold a PhD or be about to defend his/her PhD thesis by December 2009. The postdoc researcher will work within the laboratory PPS (Preuves, Programmes, Systemes) http://www.pps.jussieu.fr which is internationally recognized as one of the leading research laboratories in mathematics and computer science, with its distinctive proof-theoretic culture. The laboratory PPS is located in Chevaleret, the largest research community of mathematicians in France. The laboratory PPS is also part of the Fondation Sciences Mathematiques de Paris. http://www.sciencesmath-paris.fr Strong interaction of the postdoc researcher with the partner sites of the CHOCO project is also expected: - Laboratoire d'Informatique de Paris Nord. - Laboratoire d'Informatique du Parallelisme, Lyon, - Laboratoire de Mathematiques de l'Universite de Savoie, Chambery - Institut de Mathematiques de Luminy, Marseille, - Laboratoire d'Informatique Fondamentale de Marseille, Further information will possibly be made available from the web page of the project indicated above. [For admin and other information see: http://www.mta.ca/~cat-dist/ ]