From a.rosta@ntlworld.com Sun Aug 12 07:59:42 2001 Return-Path: X-Sender: a.rosta@ntlworld.com X-Apparently-To: lojban@yahoogroups.com Received: (EGP: mail-7_3_1); 12 Aug 2001 14:59:42 -0000 Received: (qmail 68551 invoked from network); 12 Aug 2001 14:59:41 -0000 Received: from unknown (10.1.10.26) by l10.egroups.com with QMQP; 12 Aug 2001 14:59:41 -0000 Received: from unknown (HELO mta02-svc.ntlworld.com) (62.253.162.42) by mta1 with SMTP; 12 Aug 2001 14:59:41 -0000 Received: from andrew ([62.253.90.159]) by mta02-svc.ntlworld.com (InterMail vM.4.01.03.00 201-229-121) with SMTP id <20010812145939.BNSC29790.mta02-svc.ntlworld.com@andrew> for ; Sun, 12 Aug 2001 15:59:39 +0100 To: "Lojban@Yahoogroups. Com" Subject: negating connectives Date: Sun, 12 Aug 2001 15:58:44 +0100 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 From: "And Rosta" X-Yahoo-Message-Num: 9440 As per standard logic, negating a connective reverses its truth table. E.g. E na E T T : T F T F : F T F T : F T F F : F T My question is, firstly: How do we negate a connective so as to mean "this connective yields a false/wrong truth table, but its truth-reversal does not necessarily yield a true/correct truth table"? For example, if I know that p iff q, I would like to be able to somehow say that I know that it is false/wrong that p and q. And secondly: In asking the first question, am I falling victim to the fallacy of construing connectives as possible-worlds operators, so that the answer to my question needs to be sought amid the logic of possible-world operators rather than the logic of connectives? --And.