Summary: Caching and Lemmaizing in Model Elimination
Theorem Provers ?
Owen L. Astrachan 1 and Mark E. Stickel 2
1 Department of Computer Science, Duke University, Durham, NC 27706,
ola@cs.duke.edu
2 Artificial Intelligence Center, SRI International, Menlo Park, CA. 94025,
stickel@ai.sri.com
Abstract. Theorem provers based on model elimination have exhibited
extremely high inference rates but have lacked a redundancy control
mechanism such as subsumption. In this paper we report on work done
to modify a model elimination theorem prover using two techniques,
caching and lemmaizing, that have reduced by more than an order of
magnitude the time required to find proofs of several problems and that
have enabled the prover to prove theorems previously unobtainable by
top­down model elimination theorem provers.
1 Introduction
Model Elimination (ME) [17, 19] is a complete inference procedure for the first­
order predicate calculus. It is the method underlying the Prolog Technology The­
orem Prover (PTTP) [28, 29], the SETHEO prover [16], and several or­parallel
theorem provers [26, 9, 2]. The use of model elimination, an input proof pro­

Source: Astrachan, Owen - Department of Computer Science, Duke University

Collections: Computer Technologies and Information Sciences