Relaxing restrictions on invariant composition in the B method by ownership control a la Spec#

Abstract

This paper deals with modular verification of component invariants in the B Method. On the one hand, B imposes severe architecture restrictions that ensure soundness of component compositions with a few additional proof obligations. On the other hand, in the context of the verification of object oriented programs, Spec# proposes a more expressive approach, but at the price of more complex specifications, and more numerous proof obligations. In this paper, we investigate an intermediate solution combining the advantages of both approaches. © 2009 Springer-Verlag.