Message-Id: <199502251937.AA17644@nfs1.digex.net>
From: jorge@PHYAST.PITT.EDU
Date: Sat Feb 25 14:37:12 1995
Subject:      Re: On {lo} and existence
X-From-Space-Date: Sat Feb 25 14:37:12 1995
X-From-Space-Address: LOJBAN%CUVMB.BITNET@uga.cc.uga.edu

And:
> > I don't understand. Suppose I dream that I'm a woman. Then
> > it is true that {lo ninmu cu nanmu} right?
>
> Only if in the dream there is a woman that is a man, and this is
> possible in the dream world.

Everything is possible in the dream world, so that is not a
restriction, but anyway, this is what I meant:

        mi senva lo ninmu no'u mi
        ije  mi nanmu
        i seni'ibo lo ninmu cu nanmu

> I thought you wished to argue that {ro broda cu broda} must
> be true. I suppose you mean that under my current position
> it must be false.

That's right. I think {ro broda cu broda} must be true under
a rational interpretation of {ro broda}, while it must be false
if you allow {ro broda} to mean "everything that is a broda
in the universe I have in mind".

> Well, it needn't be false. Here's why.
> This is what I'm claiming {ro broda cu broda} entails:
>
>   U [an in-mind constant] is a universe. In U there is a set, s.
>   For every x, if, in U, x is a broda, then x is a member of s.
>   R [an in-mind constant] is what we are currently taking to be
>   the real universe.
>   In R, very member of x is a broda.
>
> If U = R, then {ro broda cu broda} is true.

So we must be able to read minds in order to know whether
{ro broda cu broda} is true? How do I know if you are taking
U = R or not?

Would you say that {ro mlatu cu mlatu} is true or not?
Under your interpretation, it is impossible to know unless
the speaker tells us from what universe are his cats of
{ro mlatu}. In fact, the speaker could say {no mlatu cu mlatu}
and it could be true with your interpretation.

> Let's look at your proof:
> > For the broda under consideration, find a ko'a such that
> > {ko'a broda} is false.
> Okay. Koha = me, AR. Broda = ninmu.
> > Now imagine a universe where {ko'a broda} is true.
> Ok. Recalling dreams of confused adolescence....
> > Then {ro broda cu broda} must be false, because there is at
> > least one {lo broda}, namely ko'a, which na broda.
>
> {ro ninmu cu ninmu} can be true in both real world and this
> dream world where I'm a ninmu, so long as the universe in which
> the membership of the set containing lahe {ro ninmu} is the
> same as the universe in which these members are ninmu. I.e. if
> universe U is universe R.

But we are considering the case where U is not the same as R.
U is the dream where you are a ninmu. Then clearly in this
universe R, {ro ninmu cu ninmu} is false.

The question is, how do we know whether {ro ninmu cu ninmu} is true
or false? Do we only examine R, or do we have to additionally
ask the speaker to tell us what U is? If the latter, then no
truth values of statements involving {lo} can be decided by anyone
but the speaker.

> I see what you're saying. The problem comes from taking {lo broda}
> to mean:
>
>   Ex, x is a universe, and in x, Ey, y is a broda
>
> - according to which everything you say is true, whereas I think it
> should mean:
>
>   In universe U, Ey, y is a broda.
>
> - in which case, to test whether {lo broda cu brode} is true, you
> first have to ascertain which universe is U.

So you agree that no statement involving {lo} has a truth value other
than the one the speaker chooses.

> > What is the point of having {lo} if every claim made with it
> > is vacuously true?
> None at all, but I don't think every claim made with it is vacuously
> true.

Ok, its truth value is decided exclusively by the speaker, independently
of what goes on in R. I don't see the point of that either.

> "I described
> my wings" doesn't entail "I have wings".

It does in English. If you say "My wings are yellow with purple dots"
I will ask "You have wings???". You can't say "I don't have wings,
but they are very pretty".

> If they can't both
> be true, then {lo nu} must denote something that really happens.
> That would be very inconvenient.

Unless {nu <bridi>} means "x1 is a potential event of <bridi>".
Potential in R, independently of whether it happens or not in some U.

But I agree that {lo nu} should denote something that really happens.
Unfortunately, usage probably will decide against that.

Jorge