Message-Id: <m0qOqTt-000022C@xiron.pc.helsinki.fi>
Date:         Fri, 15 Jul 1994 12:50:27 EDT
Reply-To:     jorge@PHYAST.PITT.EDU
Sender:       Lojban list <LOJBAN%CUVMB.bitnet@FINHUTC.hut.fi>
From:         Jorge Llambias <jorge@PHYAST.PITT.EDU>
Subject:      Re: cukta
To:         lojban@cuvmb.cc.columbia.edu
Content-Length: 2453
Lines: 65

> From dave@VFL.Paramax.COM Fri Jul 15 10:45:28 1994
> To: jorge@phyast.pitt.edu
> Subject: Re: cukta

(Dave, I think you meant to send this to the list, so I post your whole
message. The default setting for replies is to the original sender,
rather than to the list.)

>
>
> Bob Slaughter:
> >>
> >> I just noticed that we may be confusing *semantic* truth with logical
> >> truth.
> >>
> >> The statement "I am a Klingon" is *logically* true, because it is
> >> gramatically properly formed, hence semantic input (wherther I am a
> >> Klingon or not) gives meaningful output.
>
> Since you say the book you read this in is currently packed away, I
> suggest that you are misremembering the terminology, or that the author
> did not manage to make his point very clearly.  Check it out when you
> unpack the book.
>
>
> Jorge:
> >
> > I would prefer to say that it is logically valid, rather than true, but the
> > idea is the same. This is related to Colin's +/-features. If there is a
> > conflict, then the statement fails logically, and asking about its semantic
> > truth is almost meaningless.
>
> Logicians argue as much as anyone, but there is nevertheless a fairly
> wide consensus on basic terminology.
>
> "I am a Klingon" is *well-formed*, because it is possible meaningfully
> to assign a truth value to it.  It is NOT, however, "xxxx-true" for
> any xxxx that I have ever heard of.  (Actually, "well-formed" applies
> to statements already cast in logical terms; it is something of an
> extension of the meaning of "well-formed" to apply it to a natural-language
> statement, to claim that the statement can in fact be turned into a
> well-formed formula in the predicate calculus.)
>
> "I am a Klingon; All Klingons are ugly; therefore, I am ugly" is a
> *valid* logical argument.  The concept of validity applies to
> arguments, not statements.
>
>   --dave
>


That sounds right. I think what I was trying to say has nothing much to
do with logic, in fact.

I don't know if *well-formed* is the best way to put it, but this is what
I meant:

The lojban sentence {mi cusku li mu} is grammatical, but fails in the
category matching. It doesn't mean "I say 'five'". That would be
{mi cusku zo mu}. As far as I understand, it is a meaningless sentence,
although grammatical, so to say that it is true or false is also
meaningless. I don't know if we could say that it's *ill-formed*, but
there's definitely something wrong with it.

Jorge