From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Original-To: caml-list@yquem.inria.fr Delivered-To: caml-list@yquem.inria.fr Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by yquem.inria.fr (Postfix) with ESMTP id 6F645BB81 for ; Wed, 11 Jan 2006 09:34:32 +0100 (CET) Received: from pauillac.inria.fr (pauillac.inria.fr [128.93.11.35]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id k0B8YWa8028896 for ; Wed, 11 Jan 2006 09:34:32 +0100 Received: from nez-perce.inria.fr (nez-perce.inria.fr [192.93.2.78]) by pauillac.inria.fr (8.7.6/8.7.3) with ESMTP id JAA23190 for ; Wed, 11 Jan 2006 09:34:31 +0100 (MET) Received: from mail.tcs.inf.tu-dresden.de (tcs01.inf.tu-dresden.de [141.76.75.1]) by nez-perce.inria.fr (8.13.0/8.13.0) with ESMTP id k0B8YVQ6028893 for ; Wed, 11 Jan 2006 09:34:31 +0100 Received: from localhost (localhost [127.0.0.1]) by mail.tcs.inf.tu-dresden.de (Sun Java System Messaging Server 6.1 HotFix 0.06 (built Nov 11 2004)) with ESMTP id <0ISX00B6A6HILX00@mail.tcs.inf.tu-dresden.de> for caml-list@inria.fr; Wed, 11 Jan 2006 09:34:30 +0100 (MET) Received: from tcs01.inf.tu-dresden.de ([127.0.0.1]) by localhost (mail.tcs.inf.tu-dresden.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 23067-06 for ; Wed, 11 Jan 2006 09:34:30 +0100 (MET) Received: from ithif59.inf.tu-dresden.de (ithif59.inf.tu-dresden.de [141.76.75.59]) by mail.tcs.inf.tu-dresden.de (Sun Java System Messaging Server 6.1 HotFix 0.06 (built Nov 11 2004)) with ESMTPS id <0ISX00BGE6HI2C00@mail.tcs.inf.tu-dresden.de> for caml-list@inria.fr; Wed, 11 Jan 2006 09:34:30 +0100 (MET) Received: from tews by ithif59.inf.tu-dresden.de with local (Exim 4.50) id 1EwbR8-0001Uo-9o for caml-list@inria.fr; Wed, 11 Jan 2006 09:34:30 +0100 Date: Wed, 11 Jan 2006 09:34:30 +0100 From: Hendrik Tews Subject: Re: [Caml-list] Coinductive semantics In-reply-to: <43C3963D.5030601@tsc.uc3m.es> To: caml-list@inria.fr Message-id: MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7BIT X-Virus-Scanned: amavisd-new at tcs.inf.tu-dresden.de References: <43BD6418.4090407@barettadeit.com> <43BE6CAB.2030503@andrej.com> <43C3963D.5030601@tsc.uc3m.es> User-Agent: Gnus/5.09 (Gnus v5.9.0) Emacs/21.4 X-Miltered: at nez-perce with ID 43C4C318.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Miltered: at nez-perce with ID 43C4C317.000 by Joe's j-chkmail (http://j-chkmail.ensmp.fr)! X-Spam: no; 0.00; hendrik:01 tews:01 tews:01 caml-list:01 coinductive:01 semantics:01 valverde:01 algebra:01 constructors:01 datatypes:01 descriptors:01 datatypes:01 semantics:01 coalgebraic:01 hendrik:01 X-Spam-Checker-Version: SpamAssassin 3.0.3 (2005-04-27) on yquem.inria.fr X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=none autolearn=disabled version=3.0.3 "Francisco J. Valverde Albacete" writes: although I may be out on a limb here, I recall reading *somewhere* :( that while initial algebras where good models for stateless abstract data types (and (structural) induction the way to work over terms in the free algebra defined by constructors modulo the laws of the ADT), final algebras where good models for *stateful* datatypes (and coinduction the way to work over the finer "state descriptors" modulo the laws of state equivalence), hence they *might* be better models for *objects* (as stateful datatypes) than initial algebras. That's precisely what many people in the field of coalgebras believe. There are many papers on coalgebras as semantics for object-orientation. There are coalgebraic specification languages with an OO touch, etc. Hendrik Tews