mwang@watmath.UUCP (mwang) (11/13/84)
_D_E_P_A_R_T_M_E_N_T _O_F _C_O_M_P_U_T_E_R _S_C_I_E_N_C_E
_U_N_I_V_E_R_S_I_T_Y _O_F _W_A_T_E_R_L_O_O
_S_E_M_I_N_A_R _A_C_T_I_V_I_T_I_E_S
_A_R_T_I_F_I_C_I_A_L _I_N_T_E_L_L_I_G_E_N_C_E _S_E_M_I_N_A_R
- Monday, November 19, 1984.
Mr. J.P. Delgrande of the University of Toronto will
speak on ``A Foundational Approach to Conjecture and
Knowledge in Knowledge Bases''.
TIME: 3:30 PM
ROOM: MC 6091A
ABSTRACT
This talk addresses fundamental problems concerned with
the formation, incorporation and use of conjectural
knowledge in a knowledge base. In the approach taken,
the problems of forming and maintaining a set of con-
jectures, or theory, of a domain are separated from
those of reasoning with such a theory. With regard to
forming a theory, a logical language for constraining
and interrelating a set of consistent hypotheses, or
theory, of a domain is derived. Using the algebra and
corresponding logic relating the terms of this
language, it is shown that the approach allows a basic,
yet broad and interesting, set of potential conjec-
tures. Moreover, it is argued that the restoration of
consistency of a theory in the face of conflicting evi-
dence may be carried out 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 mapping 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.