Message-Id: <199310201100.AA01249@eli.CS.YALE.EDU>
Date:         Wed, 20 Oct 1993 06:47:03 -0400
Reply-To: Logical Language Group <lojbab@ACCESS.DIGEX.NET>
Sender: Lojban list <LOJBAN%CUVMB.bitnet@YaleVM.YCC.YALE.EDU>
From: Logical Language Group <lojbab@ACCESS.DIGEX.NET>
Subject:      Re: TECH: (attention Ivan!) demonstrative predicate cmavo needed?
To: Erik Rauch <rauch>
Status: RO

John wrote his comments on predicate demonstratives before talking to
me, and I apparently wasn't too clear.  "me ta" doesn't really work, but
again it can if you don't mind a non-predictae feel to the language.
The problem is that "ta" and relatives is a sumti - and we tend in the
absence of semantic context to assume that a sumti is a 'thing' and not
a relationship.

If I point in some direction and say "ta", people will focus on a
'thing' in that direction.  But if my intent is to call attention to a
_relationship_ in that direction, I have no way to clearly do it, UNLESS
I shop around for a predicate that forces a predicative place.  Thus,
for the usage "do it this way and not that way" you can express it using
"ta'i ti .enai ta" and the fact that tadji takes a predicate means that
you are OK more or less.  But what if what you want to say about the
demonstrated relationship is something that doesn't handily have such a
semantic clue based on how you insert it into the sentence.

Put another way, for most of the large classes of anaphora, we have
correspondences at the sumti and at the selbri level:

sumti          selbri
da              bu'a
zo'e            co'e
ma              mo
ko'a            broda
ri              go'i

We don't have the selbri equivalent of "di'u", but this is a restricted
enough semantics that we can paraphrase it easily - since we are always
talking about an expression.

But the big hole I noticed is the lack of a match for ta.

Now Lojban doesn't pretend to handle all of 2nd order predicate logic,
i.e. the ability to talk about predicates as fully and logically as we
can talk about arguments.  But when I WAS able to see an easy way to
express this in a natlang (Russian) and NOT in Lojban, it seemed jarring
that Lojban should be LESS capable in talking about something logically
than a natlang.

lojbab