From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/6048 Path: news.gmane.org!not-for-mail From: "Pym, Professor David J." Newsgroups: gmane.science.mathematics.categories Subject: Re: "Databases are Categories" Date: Sun, 15 Aug 2010 19:25:43 +0100 Message-ID: References: Reply-To: "Pym, Professor David J." NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable X-Trace: dough.gmane.org 1281941546 16509 80.91.229.12 (16 Aug 2010 06:52:26 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Mon, 16 Aug 2010 06:52:26 +0000 (UTC) To: "categories@mta.ca" Original-X-From: majordomo@mlist.mta.ca Mon Aug 16 08:52:23 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from smtpx.mta.ca ([138.73.1.138]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1OktYU-0004YA-R9 for gsmc-categories@m.gmane.org; Mon, 16 Aug 2010 08:52:23 +0200 Original-Received: from mlist.mta.ca ([138.73.1.63]:58310) by smtpx.mta.ca with esmtp (Exim 4.71) (envelope-from ) id 1OktVq-0003oD-Rz; Mon, 16 Aug 2010 03:49:38 -0300 Original-Received: from majordomo by mlist.mta.ca with local (Exim 4.71) (envelope-from ) id 1OktVm-00066u-6d for categories-list@mlist.mta.ca; Mon, 16 Aug 2010 03:49:34 -0300 Thread-Topic: categories: Re: "Databases are Categories" In-Reply-To: Accept-Language: en-US Content-Language: en-US Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:6048 Archived-At: John Cartmell (who introduced contextual categories and generalized algebra= ic theories as models of dependent types in his 1978 Oxford D.Phil thesis a= nd a 1986 Ann. Pure App. Logic paper) worked on topics related to this thre= ad some years ago. Another 1986 paper, 'Formalizing the Network and Hierarc= hical Data Models --- an Application of Categorical Logic', CATEGORY THEORY= AND COMPUTER PROGRAMMING LNCS, 1986, Volume 240/1986, 466-492, DOI: 10.1007/3-540-17162-2_138, can b= e found via the following link: http://www.springerlink.com/content/y31234tkk63wp56k/ 'Abstract. We have noted that data modelling and conceptual modelling have = content and performance as their concerns. For the different data models, t= he Network and the Hierarchic, we have given logics involving the operation= s which are physically supported according to the data model. The logics ar= e sensitive to performance in a way that classical logic is not. We have no= w suggested how we might formalise this. Network and Hierarchical databases= have the functional inverse or family as their primitive of organisation. = To formalise the Network model we have given a general definition of networ= k category which seems to generalise correctly the hierarchical logic of co= ntextual categories.' There is also relevant work on categories and logic programming. David Pym -- Professor David J. Pym, MA, PhD, ScD, FBCS, CITP, FIMA, CMath, CSci 6th Century Chair in Logic University of Aberdeen Scotland +44 (0)1 224 27 4577 d.j.pym@abdn.ac.uk http://www.abdn.ac.uk/~csc335 The University of Aberdeen is a charity registered in Scotland, No SC013683= . [For admin and other information see: http://www.mta.ca/~cat-dist/ ]