From cowan@ccil.org Wed Oct 31 12:15:45 2001 Return-Path: X-Sender: cowan@mercury.ccil.org X-Apparently-To: lojban@yahoogroups.com Received: (EGP: mail-8_0_0_1); 31 Oct 2001 20:15:45 -0000 Received: (qmail 10237 invoked from network); 31 Oct 2001 20:15:43 -0000 Received: from unknown (10.1.10.27) by 10.1.1.220 with QMQP; 31 Oct 2001 20:15:43 -0000 Received: from unknown (HELO mercury.ccil.org) (192.190.237.100) by mta2 with SMTP; 31 Oct 2001 20:15:43 -0000 Received: from cowan by mercury.ccil.org with local (Exim 3.12 #1 (Debian)) id 15z1m9-0006MF-00 for ; Wed, 31 Oct 2001 15:15:49 -0500 Subject: Re: [lojban] Bald men In-Reply-To: from "James F. Carter" at "Oct 31, 2001 11:48:02 am" To: lojban@yahoogroups.com Date: Wed, 31 Oct 2001 15:15:49 -0500 (EST) X-Mailer: ELM [version 2.4ME+ PL66 (25)] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Message-Id: X-eGroups-From: John Cowan From: John Cowan X-Yahoo-Profile: johnwcowan X-Yahoo-Message-Num: 11820 James F. Carter scripsit: > As pc points out, English speakers could interpret the sentence two ways: > "each and every man doesn't have hair", or "it's not true that every man > has hair". A logician would pick the first one, Lojban is a logical > language, and the Lojban text is constructed accordingly. This is about how logicians construe English, not what "ro nanmu na se kerfa" means. > > which prenexes as > > naku ro da poi nanmu zo'u kerfa da > > No, it doesn't. The author hoped for the second interpretation, but has > failed to use De Morgan's rules when re-ordering a negated sentence: DeMorgan doesn't apply. This is one of the things that we changed from Loglan to Lojban. In Loglan, "no" was always at the beginning of the sentence: no raba jia mrenu ga -hair (I forget the Loglan for hair). Lojban moved it *syntactically* to just before the predicate, but *semantically* it still negates the whole sentence as it stands, without any DeMorgan. The position of naku, OTOH, is the same semantically as it is syntactically, and you have to use DeMorgan if you move a naku past a quantifier or logical connective. All this is laid out in the Codex Woldemar. -- John Cowan http://www.ccil.org/~cowan cowan@ccil.org Please leave your values | Check your assumptions. In fact, at the front desk. | check your assumptions at the door. --sign in Paris hotel | --Miles Vorkosigan