We present a Hoare logic that extends program specifications with regular
expressions that capture behaviors in terms of sequences of events that arise
during the execution. The idea is similar to session types or process-like
behavioral contracts, two currently popular research directions. The approach
presented here strikes a particular balance between expressiveness and proof
automation, notably, it can capture interesting sequential behavior across
multiple iterations of loops. The approach is modular and integrates well with
autoactive deductive verification tools. We describe and demonstrate our
prototype implementation in SecC using two case studies: A matcher for E-Mail
addresses and a specification of the game steps in the VerifyThis Casino
challenge