[comp.ai.digest] Seminar - Implementing Theorem Provers in Logic

dale@LINC.CIS.UPENN.EDU (Dale Miller) (10/23/87)

	  Implementing Theorem Provers in Logic Programming
			Dissertation Proposal

			      Amy Felty
		      (felty@linc.cis.upenn.edu)
		   Computer and Information Science
		      University of Pennsylvania


Logic programming languages have many characteristics that indicate
that they should serve as good implementation languages for theorem
provers. For example, they are based on search and unification which
are also fundamental to theorem proving.  We show how an extended
logic programming language can be used to implement theorem provers
and other aspects of proof systems for a variety of logics. In this
language first-order terms are replaced with simply-typed
lambda-terms, and thus unification becomes higher-order unification.
Also, implication and universal quantification are allowed in goals.
We illustrate that inference rules can be very naturally specified,
and that the search operations based on this language correspond to
those needed for searching for proofs.  We argue on several levels
that this extended logic programming language provides a very suitable
environment for implementing tactic style theorem provers. Such
theorem provers provide extensive capabilities for integrating
techniques for automated theorem proving into an interactive proof
environment.  We are also concerned with representing proofs as
objects. We illustrate how such objects can be constructed and
manipulated in the logic programming setting. Finally, we propose
extensions to tactic style theorem provers in working toward the goal
of developing an interactive theorem proving environment that provides
a user with many tools and techniques for building and manipulating
proofs, and that integrates sophisticated capabilites for automated
proof discovery. Many of the theorem provers we present have been
implemented in the higher-order logic programming language Lambda
Prolog.

Date:      Friday November 6, 1987
Location:  554 Moore
Time:      1:30 PM
Committee: Val Breazu-Tannen
	   Robert Constable
	   Jean Gallier (Chair)
	   Andre Scedrov
Advisor:   Dale Miller