LENAT@SU-SCORE.ARPA@sri-unix.UUCP (10/07/83)
From: Doug Lenat <LENAT@SU-SCORE.ARPA>
[Reprinted from the SU-SCORE bboard.]
Professor Lotfi Zadeh, of UCB, will be giving the CS colloquium this
Tuesday (10/11). As usual, it will be in Terman Auditorium, at 4:15
(preceded at 3:45 by refreshments in the 3rd floor lounge of Margaret
Jacks Hall).
The title and abstract for the colloquium are as follows:
Reasoning With Commonsense Knowledge
Commonsense knowledge is exemplified by "Glass is brittle," "Cold is
infectious," "The rich are conservative," "If a car is old, it is
unlikely to be in good shape," etc. Such knowledge forms the basis
for most of human reasoning in everyday situations.
Given the pervasiveness of commonsense reasoning, a question which
begs for answer is: Why is commonsense reasoning a neglected area in
classical logic? Because, almost by definition, commonsense
knowledge is that knowledge which is not representable as a
collection of well-formed formulae in predicate logic or other
logical systems which have the same basic conceptual structure as
predicate logic.
The approach to commonsense reasoning which is described in the talk
is based on the use of fuzzy logic -- a logic which allows the use of
fuzzy predicates, fuzzy quantifiers and fuzzy truth-values. In this
logic, commonsense knowledge is defined to be a collection of
dispositions, that is propositions with suppressed fuzzy quantifiers.
To infer from such knowledge, three basic syllogisms are developed:
(1) the intersection/product syllogism; (2) the consequent
conjunction syllogism; and (3) the antecedent conjunction syllogism.
The use of these syllogisms in commonsense reasoning and their
application to the combination of evidence in expert systems is
discussed and illustrated by examples.