From: "x" Newsgroups: comp.databases.theory References: <4b45d3ad.0405111118.1851852f@posting.google.com> <4b45d3ad.0405112026.3cfbdce1@posting.google.com> <%4noc.3394$NK4.266295@stones.force9.net> <8a529bb.0405121055.55bd1d93@posting.google.com> <40a4fd70.3221982@news.wanadoo.es> <3r7pc.23$7Q3.165@news.oracle.com> <40a51057.8060810@news.wanadoo.es> <8a529bb.0405160919.73cf214b@posting.google.com> Subject: Re: Transitive Closure Date: Mon, 17 May 2004 15:34:31 +0300 Lines: 14 X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2800.1409 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1409 NNTP-Posting-Host: 81.196.98.200 X-Original-NNTP-Posting-Host: 81.196.98.200 Message-ID: <40a8b089@post.usenet.com> X-Trace: post.usenet.com 1084797065 81.196.98.200 (17 May 2004 07:31:05 -0500) Organization: Usenet.com http://www.usenet.com 100,000+ UNCENSORED Newsgroups. The #1 Usenet Service on the Planet! X-Comments: This message was posted through Usenet.com's, FREE publicly accessible Usenet Server - "post.usenet.com" X-Comments2: IMPORTANT: Usenet.com does not condone, nor support, spam or any illegal or copyrighted postings. X-Comments3: IMPORTANT: Under NO circumstances will postings containing illegal or copyrighted material through this service be tolerated!! X-Report: Please report illegal or inappropriate use to X-Abuse-Info: Please be sure to forward a copy of ALL headers, INCLUDING the body (DO NOT SEND ATTACHMENTS) Path: newssvr20.news.prodigy.com!newsmst01a.news.prodigy.com!prodigy.com!atl-c02.usenetserver.com!news.usenetserver.com!feed5.newsreader.com!newsreader.com!news-out2.nntp.be!local!post.usenet.com!not-for-mail Xref: newssvr20.news.prodigy.com comp.databases.theory:26777 **** Post for FREE via your newsreader at post.usenet.com **** "Alfredo Novoa" wrote in message news:e4330f45.0405161549.7f66ece8@posting.google.com... > The commutative property does not make sense with unary operators like > TClose. Unary operators are always commutative because there is only > one operand's order. Commutativity does make sense with unary operators. M--f-->M--g-->M fg = gf or fg != gf -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-= *** Usenet.com - The #1 Usenet Newsgroup Service on The Planet! *** http://www.usenet.com Unlimited Download - 19 Seperate Servers - 90,000 groups - Uncensored -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=