Full Abstractness of an Interleaving Semantics for Action Refinement

For an abstract programming language with action reenement both an operational and a denotational semantics are given. The operational semantics is based on an SOS-style transition system speciication involving syntactical reenement sequences. The denotational semantics is an interleaving model which uses semantical reenementènvironments'. It identiies those statements which are equal under all reenements. The denotational model is shown to be fully abstract with respect to the operational one. The underlying metric machinery is exploited to obtain this full abstractness result. Usually, action reenement is treated either in a model with some form of true concurrency, or, when an interleaving model is applied, by assuming that the reening statements are at-omized. We argue that an interleaving model without such atomization is attractive as well.