Extending B with Control Flow Breaks

摘要

This paper describes extensions of the B language concerning control flow breaks in implementations and specification of operations with exceptional behaviors. It does not claim to define those extensions in a pure formal and complete way. It is rather a presentation of what could be done and how it could be done. A syntax is proposed and proof obligations are defined using a weakest precondition calculus extended to deal with abrupt termination. Examples emphasizing the advantages of these extensions are also given.