non-existance predications

[Logical Language Group <lojbab@access.digex.net>]

>If you are saying, There are no fairies, you CAN'T say lo crida na
>zasti, because that's logical contradiction.  IMHO.  I don't know the
>current consensus on this.

Since the "na" has scope of the entire bridi, there is no problem.  It
converts to "naku lo crida zo'u lo crida cu zasti" "It is not the case
that:  for something that is a fairy, that fairy exists."

The problem arises if you have a selbri which requires non-existance.
Let us say that "nalzasti" is such a selbri (at one time "xanri" had
this meaning).  Then:  "lo crida cu nalzasti" could cause a problem if
there are no such things as fairies.  I'm not sure it does, because for
me, the equivalent "lo crida zo'u lo crida cu nalzasti", the prenexing
in the "lo crida" form contains no stronger claim of existence than it
does in the main text.  But in the "da poi" form there is a clear
problem:  da poi crida zo'u da nalzasti clearly is false because you
have postulated the existance of da in the prenex, then said that da
not-exists, contradicting yourself.

Question for pc then:  in standard logic, does a non-quantified variable
in the prenex claim its existance, or merely cite a variable without
claiming reference.  If the latter, then we have identified a slight,
almost trivial, difference between lo broda and da poi broda.

lojbab