In a message dated 10/31/2001 1:55:06 PM Central Standard Time, jimc@MATH.UCLA.EDU writes:
As pc points out, Englishspeakers could interpret the sentence two ways: Actually, logicians regularly pick the second, as do linguists, by and large. <Subj: Re: [lojban] Bald men Date: 10/31/2001 1:55:06 PM Central Standard Time From: jimc@MATH.UCLA.EDU (James F. Carter) To: lojban@yahoogroups.com 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.> Well, yes it does. Remember that the {na} next to the selbri (andthe on on the following connective) are actually ALREADY at the leftmost end of the prenex. All the quantifiers are thus already correct for that position -- it is remembering that that is the problem, rather than the shifting problem (which comes with moving {naku} back rightward. <> It is false that for each X that is a man, (something) is X's hair > which is true: some men are bald.> Correct. <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.> This is the other version, not the one we started with. This could also be {roda poi nanmu zo'u naku kerfu da} to get the feel of the English. |