Conditions for appropriateness of speech acts in Elephant

We want sufficient conditions for use of each kind of
speech act by Elephant programs and also sufficient
conditions on the use of speech acts by the interlocutor
so that error will be avoided.  It seems the situation
may not be as simple as advertised in the current
Elephant paper.  Instead of being able to generate
a single sentence from the Elephant program that asserts that
it uses a certain kind of speech act correctly, we can
get sentences corresponding to a variety of appropriateness
conditions.  We are more interested in catching bugs in
the program than in catching inadequacies.

Consider questions and answers.

It would be nice if questions could avoid presumptions, e.g.
we want to avoid ``Have you stopped beating your wife?''
both as a question the Elephant program has to answer and
as a question it would emit.  However, doing this
completely seems to require an unpleasntly prolix style.
Thus we would like to allow, ``What is Mike's telephone
number?'' even though it involves the presumption that
there is exactly one Mike and he has exactly one
telephone number.  Under some circumstances, we would
like the program to reply ``Work or home?''  Therefore,
we should be able to give a form of correctness that
doesn't forbid it.

The obvious syntax for some questions is

what(telephone Mike)

and

where(Mike),

although the latter is ambiguous (or context dependent) with regard to
the extent of time being referred to.  Thus we might have the answers

He's a professor at Stanford.
He's spending the  semester in Austin.
Today he's in Washington.
Now he's in a meeting at DARPA.
At this moment, he's in the bathroom.

Even more detail can be requested by asking ``What is Mike's
physical position'' soliciting answers like ``He's lying on
his back with his feet dangling off the edge of the boat.''

Here are some of the things that might be asked about the
appropriateness of answers.

1. Will they be true when the program is run?  This
requires assumptions about the reliability of the program's
sources of information.

2. Will they be honest?  Will they be in accordance with
the beliefs of the program at the time?

3. Will they be responsive?

4. The key fact about an answer is that the questioner
should then know the answer to his question.  Thus
we ask whether Pat now knows Mike's telephone number.
This doesn't solve the problem, because we now have
to give conditions for knowing the phone number.

Perhaps this can be expressed by a sentence

(exists X)(X in explicit.telephone.concepts and
knows(pat,Equal(Telephone Mike,X)))

5. The next (Gricean) point is that Pat shouldn't
come to believe anything that's false by doing
reasonable nonmonotonic reasoning on what he has
been told.

6. Is there more to Grice than that?  Yes, there is, but
it's hard to see how to incorporate it in Elephant.