Deducibility Constraints

Abstract

Abstract. In their work on tractable deduction systems, D. McAllester and later D. Basin and H. Ganzinger have identified a property of inference systems (the locality property) that ensures the tractability of the Entscheidungsproblem. On the other hand, deducibility constraints are sequences of deduction problems in which some parts (formulas) are unknown. The problem is to decide their satisfiability and to represent the set of all possible solutions. Such constraints have also been used for deciding some security properties of cryptographic protocols. In this paper we show that local inference systems (actually a slight modification of such systems) yield not only a tractable deduction problem, but also decidable deducibility constraints. Our algorithm not only allows to decide the existence of a solution, but also gives a representation of all solutions.

Associative-Commutative Deducibility Constraints

“…In Section 5, we give a complete and terminating strategy. Due to a lack of space, the proofs are given in [3].…”