Program Verification with Constrained Horn Clauses (Invited Paper)

Abstract Many problems in program verification, Model Checking, and type inference are naturally expressed as satisfiability of a verification condition fragment First-Order Logic called Constrained Horn Clauses (CHC). This transforms analysis tasks to the realm first order into SMT solvers. In this paper, we give brief overview how CHCs capture for sequential imperative programs, discuss CHC solving algorithm underlying Spacer engine SMT-solver Z3.