Using a Set Constraint Solver for Program Verification

{log} is a constraint solver for an expressive theory of finite unbounded sets and binary relations. It is a complete solver for an important fragment of formulas based on operators such as equality, membership, union, domain, composition, etc. where terms are finite unbounded extensional sets and binary relations. It is also a complete solver for formulas based on equality and membership where terms are extensional and restricted intensional sets. As such {log} can automatically prove a number of theorems of the theory of finite unbounded sets and relations. In turn, the theory of finite sets and relations is known to be a very good specification language for many programs. In this paper we show how {log} can be used as an effective tool for automatically discharging verification conditions produced during the formal functional verification of imperative programs. A case study shows the application of {log} to the verification of several list functions.