Specifying and Verifying in Tuple Spaces

We propose a basis for a formal method to specify and verify programs in the framework of tuple space languages. We address three points: single out a speciication language; deene language semantics; show how to verify program properties. The speciication language is a variation of temporal logic. We build our formulae over atoms instead of propositional symbols, i.e. we work with a rst order temporal logic. Temporal relations between propositional formulae are not expressive enough to describe relations between tuple spaces, which are multisets of atoms. We x a prototype language and deene both an axiomatic and an operational semantics. The axiomatic semantics is in the weakest precondition style, and the transition system deening the operational semantics is based on the new notion of enabling precondition, which exploits the angelic choice in non-deterministic selection. We relate operational and weakest precondition semantics so that the properties derived using the axiomatic semantics are correct with respect to the operational behaviour. This result overcomes the problems related to the basic statement, which is a non-deterministic rule rather than a simple assignment. With respect to the veriication calculus, we focus in this paper on safety properties and we supply the composition rules needed to derive that a system satisses a set of safety properties.