Message-Id: <m0r0Qa6-00006tC@xiron.pc.helsinki.fi>
Date:         Thu, 27 Oct 1994 01:48:04 -0700
Reply-To:     Gerald Koenig <jlk@NETCOM.COM>
Sender:       Lojban list <LOJBAN%CUVMB.bitnet@FINHUTC.hut.fi>
From:         Gerald Koenig <jlk@NETCOM.COM>
Subject:      any
To:           Veijo Vilva <veion@XIRON.PC.HELSINKI.FI>
Content-Length: 2773
Lines: 73

Jorge quotes me(djer):

la djer cusku di'e

> su'o da zo'u tu'e da plise inaja mi cidja da
> I eat some apples. (They exist).

This is not what the Lojban sentence claims. In Lojban, you wrote:
"there is some x, such that if it is an apple, I eat it". This statement
is always true. It suffices to select some non-apple for da, and since
in that case {da plise} is false, the whole statement is true for at least
that da whether I eat it or not, and therefore the statement is true.

GK>
        What the sentence claims is:
        IF there is at least one object x such that x is an apple,THEN I
        eat x.
        I believe you have misplaced your IF.
        For my sentence to be always true it would have to be a
        tautology. It has the logical form of a material implication,
        which is by definition not a tautology. Here is a truth table
        for inaja and for a tautology, P=P.

        P Q  P=>Q  P=P
        TT    T     T
        TF    F     T
        FT    T     T
        FF    T     T

        It is possible to produce a false implication, for example, by
        saying: There is an apple, and I do not eat it. My statement is
        not trivially always true.


Jorge>
The normal way to say "I eat the apple" is {mi citka le pa plise}.
You can say {mi citka lo pa plise}, but then you really mean that only
one apple exists.

GK>     Agreed. My purpose was to express the quantifier Iota(x). This
        quantifier asserts the existence of a unique object.


Jorge>
I think by "l'alfa" and "l'sma" you mean the same I wanted to get with
{pa xe'e} and {su'o xe'e}.

GK>     Not exactly. Alpha-any means " one taken at random, or
        indiscriminately". Pa-xe'e can mean one taken according to an
        order or plan.  Sigma-any means " more than one and less than
        all." Su'o-any means "at least one". I didn't pull these
        definitions out of a hat. You can read them in a dictionary.
        Not that I ever would have even noticed the "any" problem if
        you hadn't brought it up. But I think you have found a
        fundamental deficiency in lojban in its inability to easily
        express the nuances of "any". Lojban has the same problem as
        predicate calculus in this regard. This is because it has the
        same quantificational scheme. I find it strange that I have
        wound up arguing for the change, and you seem to be opposed.

Jorge>
I don't understand why you say that one should be a quantifier and the
other an article.

GK>     It had to do with the semantic equivalence of a definite
        description and a certain combination of quantifiers with
        existence. It is a side issue and I changed my position as you
        can read in my any & every post.

 Jorge

djer