From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.science.mathematics.categories/5996 Path: news.gmane.org!not-for-mail From: Meredith Gregory Newsgroups: gmane.science.mathematics.categories Subject: Re: MSFT C9 video on a monadic approach to location Date: Mon, 19 Jul 2010 19:22:49 -0700 Message-ID: References: Reply-To: Meredith Gregory NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 (iPhone Mail 8A293) Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1279634326 25798 80.91.229.12 (20 Jul 2010 13:58:46 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Tue, 20 Jul 2010 13:58:46 +0000 (UTC) To: Vaughan Pratt , Categories Original-X-From: categories@mta.ca Tue Jul 20 15:58:45 2010 Return-path: Envelope-to: gsmc-categories@m.gmane.org Original-Received: from mailserv.mta.ca ([138.73.1.1]) by lo.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ObDLJ-0003ml-G0 for gsmc-categories@m.gmane.org; Tue, 20 Jul 2010 15:58:45 +0200 Original-Received: from Majordom by mailserv.mta.ca with local (Exim 4.61) (envelope-from ) id 1ObCpX-0006ir-Fg for categories-list@mta.ca; Tue, 20 Jul 2010 10:25:55 -0300 Original-Content-Transfer-Encoding: quoted-printable Original-Sender: categories@mta.ca Precedence: bulk Xref: news.gmane.org gmane.science.mathematics.categories:5996 Archived-At: Dear Vaughan, i should mention that for the type, M[=E2=88=82=C2=B5Mx=C2=B5M,=C2=B5M], to b= e inhabited you need some way to bottom out the recursion. In the reflective= higher-order pi-calculus that corresponds to the constant summand, 1, repre= senting the stopped process.=20 For the lambda calculus you need to do something similar -- like add in an e= xplicit distinguished representation of divergence, or add in some ground te= rms, like the booleans.=20 More generally, the trick needs to employ the option monad if the type is is= o to 1+N for appropriate N. i'm happy to provide either Haskell or Scala code to illustrate that the pro= cedure is effective. i can also provide OCaml code, but it's considerably mo= re verbose and painful to write. Best wishes, --greg Managing Partner Biosimilarity LLC [For admin and other information see: http://www.mta.ca/~cat-dist/ ]