Table of contents : Introduction....Pages 1-6 Abstract programming languages....Pages 7-45 Connections with language theory....Pages 46-60 Representation by finite automata....Pages 61-94 Representation by finite and safe Petri nets....Pages 95-117 A remark on the representation by finite Petri nets....Pages 118-122 Representation by finite and strict predicate/transition nets....Pages 123-155