Message-Id: <m0r1MGo-00006yC@xiron.pc.helsinki.fi>
Date:         Sat, 29 Oct 1994 15:26:52 -0700
Reply-To:     "John E. Clifford" <pcliffje@CRL.COM>
Sender:       Lojban list <LOJBAN%CUVMB.bitnet@FINHUTC.hut.fi>
From:         "John E. Clifford" <pcliffje@CRL.COM>
Subject:      some definitions
To:           Veijo Vilva <veion@XIRON.PC.HELSINKI.FI>
Content-Length: 2524
Lines: 39

I am having trouble following parts of the discussions here because I do
not understand some words the ways they are being used.  Since the issues
we are concerned with are logical, I find it handy to get definitions in
terms of the basics of logic: truth conditions or validated inferences.
Anyhow, here are a few terms as I use them (standard stuff, I think) and
a few requests for help with some other terms.
OPAQUE (referentially opaque context) Terms which occur in opaque
contexts cannot be exported to surrounding transparent contexts, cannot
be generalized by nor used to instantiate external quantifiers, doe not
replace under external identitities, if bound need not instantiate to
external objects.  (I admit that this collapses several notions into one,
but most logicians hold that they go together.)
EXTENSIONAL The truth of every complex is a direct function of the truth
of its constituents.  Hence, referring expressions refer to and
quantifiers range over the established domain only.  Extensional contexts
are, therefore, transparent (not opaque).
INTENSIONAL  Not extensional, for short: the truth of some complexes are
not determmined by the truth of their components. Intensional contexts
may be opaque and, so, most (I would say "all") must be treated as such.
(The exact line between extensional and intensional is controversial and
system-bound.  For example, modal and tense systems can be worked either
way, with no significant _formal_ difference).
INTENTIONAL.  Having to do with what an agent intends: purpose, goal,
motive, etc.  This somewhat elastic, since objective needs are sometimes
included along with subjective wants.  These are always intensional.

I hope that helps. Now to help me, could someone please explain what
truth conditions or inferences are involved in "opaque" as a property of
sumti(? descriptors? it is not clear what is being classified here).  In
the same discussion -- and maybe more critically -- could someone explain
"specific" and "definite".  These two words are used interchangably by
some groups and by others to make any number of distinctions (often one
group uses one to make the distinction another makes with the other),
what exactly is going on here.
The discussion is not helped by the fact that some of the examples of
apparently non-controversial cases seem just wrong: _lo_brida_ keeps
appearing as a general term rather than a singular one, if translation
and inferences are any guide.
pc>|83 Trying to be the logical brake on the wheel of change