phyllis@utcsrgv.UUCP (Phyllis Eve Bregman) (02/20/84)
UofT Department of Computer Science Seminar Schedule for
the week of February 20th, 1984
Tuesday, February 21st, 3:00 P.M., GB244: J.P. Delgrande, Department of
Computer Science, University of Toronto: "Theory formation and
and conjectural knowledge in knowledge bases".
ABSTRACT:
Abstract This talk addresses fundamental problems concerned
with the formation, incorporation and use of conjectural
knowledge in a knowledge base. A central claim is that it
is essential to separate the problems of forming and main-
taining a set of conjectures, or theory, of a domain from
those of reasoning with such a theory. With regard to form-
ing a theory, a logical language for constraining and inter-
relating a set of conjectures is derived; the formal proper-
ties of this language are used to precisely specify the set
of potential conjectures. Also, it is shown that, in the
face of conflicting evidence, the consistency of such a set
may be restored with reasonable efficiency. For reasoning
with a theory, an existent first order language that can
reason about the state of its knowledge is extended to one
that can deal with both knowledge and hypothesis. The map-
ping of the sentences of a theory into this language is
shown to be straight-forward. Finally, the overall approach
is shown to lead to an account of exceptions and exception-
allowing general statements in knowledge-based systems.
--
Phyllis Eve Bregman
CSRG, Univ. of Toronto
{decvax,linus,ihnp4,uw-beaver,allegra,utzoo}!utcsrgv!phyllis