Conservative Extension in Structural Operational Semantics

Structural operational semantics (SOS) [44] provides a framework to give an operational semantics to programming and specification languages. In particular, because of its intuitive appeal and flexibility, SOS has found considerable application in the study of the semantics of concurrent processes. SOS generates a labelled transition system, whose states are the closed terms over an algebraic signature, and whose transitions are supplied with labels. The transitions between states are obtained inductively from a transition system specification (TSS), which consists of so-called transition rules of the form premises conclusion . A typical example of a transition rule is