From jimc@MATH.UCLA.EDU Wed Oct 31 11:48:04 2001 Return-Path: X-Sender: jimc@math.ucla.edu X-Apparently-To: lojban@yahoogroups.com Received: (EGP: mail-8_0_0_1); 31 Oct 2001 19:48:03 -0000 Received: (qmail 58386 invoked from network); 31 Oct 2001 19:48:02 -0000 Received: from unknown (10.1.10.142) by 10.1.1.224 with QMQP; 31 Oct 2001 19:48:02 -0000 Received: from unknown (HELO simba.math.ucla.edu) (128.97.4.125) by mta3 with SMTP; 31 Oct 2001 19:48:02 -0000 Received: from localhost (jimc@localhost) by simba.math.ucla.edu (8.11.3/8.11.3/SuSE Linux 8.11.1-0.5) with ESMTP id f9VJm2L01645 for ; Wed, 31 Oct 2001 11:48:02 -0800 X-Authentication-Warning: simba.math.ucla.edu: jimc owned process doing -bs Date: Wed, 31 Oct 2001 11:48:02 -0800 (PST) To: Subject: Re: [lojban] Bald men In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII From: "James F. Carter" I didn't notice that this question actually got answered. On Sun, 28 Oct 2001, Invent Yourself wrote: > The naku Wiki page says the following. Is it true? jimc says: No. > "All men don't have hair" can be represented in Lojban as > ro nanmu na se kerfa 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. > 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: exchange "and" vs. "or", and likewise exchange existential vs. universal quantification. > It is false that for each X that is a man, (something) is X's hair > which is true: some men are bald. Here's my rendition: naku *su'o* da poi nanmu zo'u kerfa da It's false that for even one X which is a man, there exists Y [which is] the hair of X. All men are bald. James F. Carter Voice 310 825 2897 FAX 310 206 6673 UCLA-Mathnet; 6115 MSA; 405 Hilgard Ave.; Los Angeles, CA, USA 90095-1555 Email: jimc@math.ucla.edu http://www.math.ucla.edu/~jimc (q.v. for PGP key)