any
Gerald Koenig
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
John E. Clifford
me that we do need something more to d in Lojban what we do in English
with "any". The problem is that imperatives set up opaque contexts
without a word that sets the context. Thus, we cannot show the
quantifier outside the intensional context by putting it before the
context-forming word -- the classic way of dealing with a context leaper
in logic. Even fronting the quantifier leaves it in imperative mode: ko
cuxna ro karda = ro da poi karda gu ko cuxna da and both say "Pick every
card" (I suspect I need something stronger than just "gu" there) which is
as wrong as the forcer-deck _lo_ for what we want. We can stick with the
safe ko cuxna pa karda or su'o karda or da poi karda, but those, being in
an opaque context, need not be restricted to (or even include) the cards
actually presented.
Using the subject-raising cmavo won't help here, since we want exactly to
get out of the opaque context, not warn that we are still in it
(although, we might make it a toggle -- what is the happyface for "Yuck,
ptui"?)
I was glad to see that it seems to be accepted that opaque contexts arise
from event descriptions. It is not clear whether it is accepted
that that is the only source, as I was trying to make the case. But, in
any case, if this is to be an adequate explanation, we do need to do
something about "I saw someone playing pool", for, if that is an event
description it ruins the explanation, since it is transparent and thus it
is some factor or than event-descriptions which cause opacity. ("Obtains"
is also a problem but so strange that it can probably be handled by the
fact that "that p obtains" is in every way equipollent to just p, not
merely that the complex implies the simple.)
pc>|83 Trying to be the logical brake on the wheel of change
jo...@phyast.pitt.edu
> > su'o da zo'u tu'e da plise inaja mi cidja da
> > I eat some apples. (They exist).
xorxes:
> 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.
djer:
> 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.
What the sentence claims is:
There is at least one x such that: IF x is an apple THEN I eat x.
Notice that the quantification is in the prenex before the {tu'e}, and
therefore does not apply only to the first part but to the whole thing.
> For my sentence to be always true it would have to be a
> tautology.
No, it is not a tautology. It is always true because {da naku plise} is always
true. At least one thing is not an apple. The statement would not be always
true only in a universe where everything is an apple.
> 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.
Not my {xe'e}. The way I'd define it is something like: "Potentially everyone
but only one and no other, and none fits the predication in actuality". It is,
as you say, not definable within predicate calculus, as I understand it.
> Sigma-any means " more than one and less than all."
That sounds like {so'i}, or some other of the series.
> Su'o-any means "at least one".
{su'o} by itself already is "at least one". {su'o xe'e} would be: "Potentially
every one and it must be one or more (potentially), but none in actuality".
> I find it strange that I have
> wound up arguing for the change, and you seem to be opposed.
It wouldn't be the first time that I argue for opposing sides, but no,
I'm still in favour of {xe'e}, as long as it is not used without thinking
for every meaning of "any".
Jorge