Title
Positive Unit Hyperresolution Tableaux and Their Application to Minimal Model Generation
Abstract
Minimal Herbrand models of sets of first-order clauses are useful in several areas of computer science, for example, automated theorem proving, program verification, logic programming, databases, and artificial intelligence. In most cases, the conventional model generation algorithms are inappropriate because they generate nonminimal Herbrand models and can be inefficient. This article describes an approach for generating the minimal Herbrand models of sets of first-order clauses. The approach builds upon ipositive unit hyperresolution (iPUHR) itableaux, that are in general smaller than conventional tableaux. PUHR tableaux formalize the approach initially introduced with the theorem prover SATCHMO. Two minimal model generation procedures are described. The first one expands PUHR tableaux depth-first relying on a icomplement splitting expansion rule and on a form of backtracking involving constraints. A Prolog implementation, named MM-SATCHMO, of this procedure is given, and its performance on benchmark suites is reported. The second minimal model generation procedure performs a breadth-first, constrained expansion of PUHR (complement) tableaux. Both procedures are optimal in the sense that each minimal model is constructed only once, and the construction of nonminimal models is interrupted as soon as possible. They are complete in the following sense: The depth-first minimal model generation procedure computes all minimal Herbrand models of the considered clauses provided these models are all finite. The breadth-first minimal model generation procedure computes all finite minimal Herbrand models of the set of clauses under consideration. The proposed procedures are compared with related work in terms of both principles and performance on benchmark problems.
Year
DOI
Venue
2000
10.1023/A:1006291616338
J. Autom. Reasoning
Keywords
Field
DocType
minimal model,model generation,tableau,proof theory
Discrete mathematics,Automated theorem proving,Algorithm,Herbrand's theorem,Proof theory,Minimal model,Prolog,Logic programming,Backtracking,Mathematics
Journal
Volume
Issue
ISSN
25
1
1573-0670
Citations 
PageRank 
References 
44
1.83
47
Authors
2
Name
Order
Citations
PageRank
François Bry11428384.75
Adnan Yahya2684.77