A Metric Approach to Control Flow Semantics

The authors' monograph “Control Flow Semantics” (MIT Press 1996) gives an extensive exposition of comparative programming language semantics using techniques from metric topology. In the book Banach's fixed‐point theorem for complete metric spaces plays a prominent role in the construction and comparison of semantical models. Here we present the basic idea of exploiting Banach's theorem. The approach is illustrated with the definition of an operational and a denotational model for an abstract programming language with parallelism. Note: The work reported here is not novel, but intended to provide an introduction of the metric approach to programming language semantics for a nonspecialist audience.