Xref: utzoo sci.math:17608 sci.logic:1291 comp.theory:2026 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!think.com!spool.mu.edu!news.nd.edu!mentor.cc.purdue.edu!pop.stat.purdue.edu!hrubin From: hrubin@pop.stat.purdue.edu (Herman Rubin) Newsgroups: sci.math,sci.logic,comp.theory Subject: Re: Linear Logic Summary: Why linear logic generally does not work Keywords: Linear Logic Message-ID: <12621@mentor.cc.purdue.edu> Date: 22 May 91 14:05:16 GMT Article-I.D.: mentor.12621 References: <3023@puck.sw.mcc.com> <1991May16.232218.8032@newshost.anu.edu.au> <1991May21.222324.12820@cs.ubc.ca> Sender: news@mentor.cc.purdue.edu Followup-To: sci.math Lines: 18 There have been attempts to come up with a reasonable linear logic since at least 1919. The problem is that they run into extreme difficulties. A simple example is the truth value of X&Y, where that of X is .5, as is that of Y. Now what if Y is X? What if Y is ~X? The extension needed to take care of things like this is probability. Linear logics are possible in "Brouwerian" logic, but unless X is false, ~X is false. Negations in Brouwerian logic satisfy Boolean logic. Certainly one can define any type of system one wants, but giving it a catchy name like linear logic or fuzzy logic does not mean that is succeeds in accomplishing its ostensible purpose. -- Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399 Phone: (317)494-6054 hrubin@l.cc.purdue.edu (Internet, bitnet) {purdue,pur-ee}!l.cc!hrubin(UUCP)