“…They consist of the operational semantics Od, based on the derivation relation f-, and of the declarative semantics Deel,,, and Declfl based on model theory and fixed-point theory, respectively. The other semantics, namely the denotational semantics Den, is issued from the imperative tradition, and, more particularly, from its metric semantic branch ( [6], [5], [14], ... ). It describes computations, in a compositional way, via histories, possibly including hypotheses.…”