Incremental Rewriting Modulo SMT

Abstract

AbstractRewriting Modulo SMT combines two powerful automated deduction techniques (1) rewriting and (2) SMT-solving. Rewriting enables the specification of behavior of systems using rewriting rules, while SMT theories specify system properties. Rewriting Modulo SMT is enabled by combining existing tools, such as Maude and SMT solvers. Search algorithms used for carrying out Rewriting Modulo SMT, however, cannot exploit the incremental solving features available in SMT solvers as they are based on breadth-first search. This paper addresses this limitation by proposing Incremental Rewriting Modulo SMT Theories, which is a syntactical restriction to rewriting rules. This restriction turns out to naturally be used in several applications of Rewriting Modulo SMT, including the verification of algorithms, cyber-physical systems, and security protocols. Moreover, we propose a Hybrid-Search algorithm for Incremental Rewriting Modulo SMT Theories that combines breadth-first search and depth-first search, thus enabling incremental SMT-solving. We demonstrate through a collection of existing benchmarks that the Hybrid-Search algorithm can achieve a 10 times performance improvement in verification times.