Message-Id: <m0riibF-00001pC@xiron.pc.helsinki.fi>
Date:         Sun, 26 Feb 1995 12:59:31 +0000
Reply-To:     ucleaar <ucleaar@UCL.AC.UK>
Sender:       Lojban list <LOJBAN%CUVMB.bitnet@FINHUTC.hut.fi>
From:         ucleaar <ucleaar@UCL.AC.UK>
Subject:      Re: On {lo} and existence
To:           Veijo Vilva <veion@XIRON.PC.HELSINKI.FI>
In-Reply-To:  (Your message of Sat, 25 Feb 95 14:38:53 EST.)
Content-Length: 5071
Lines: 121

Jorge:
> > 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,

It depends on the dream world. In some dream worlds not everything is
possible.

> but anyway, this is what I meant:
>        mi senva lo ninmu no'u mi
>        ije  mi nanmu
>        i seni'ibo lo ninmu cu nanmu

It can't be true in this world, but there might be some world in which
this could be true.

> > 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?

The process is analogous to deciding whether {le nanmu cu ninmu}
is true. First the hearer must ascertain who {le nanmu} refers to.
In other words, {lo broda} means "there is something that in a
certain [+specific] universe is a broda".

> 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.

This is correct.

> > 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.

With this U, it is indeed false. But the point is that not every
duhu derived from this seduhu need be false, or true.

> 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.

We must know what U is, if we want to know whether {ro ninmu cu
ninmu}, or anything else with a {lo} in, is true. The matter of
how we know what U is is a separate issue: the hearer may know
from context what it is, or may ask the speaker. As I said above,
this is how +specifics work.

> > 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.

Not at all. The speaker doesn't choose the truth value. The truth
value depends on the state of certain universes.

> > "I described my wings" doesn't entail "I have wings".
> It does in English.

To be more precise, in English "I described my wings" does not
entail "In the world where I described my wings, I have wings".
That is, in this real world I can truthfully say "I described
my wings".

> 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".

That's right. It's only certain things like describees that don't
have to exist in the same universe as the universe in which the
main predication obtains.

> > 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.

You'd have to explain to me how one ascertains whether something
is potential.

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

This, you will realize, is why I, having originally taken the same
position as you, have elected to support the opposing view.

---
And