A coalgebraic introduction to CSP

The paper presents a first step of a coalgebraic analysis of the concept of communicating sequential processes as introduced by Hoare in 3]. We make apparent the strong relationship between CSP and partial automata, i.e., special coalgebras. Thereby it turns out that 3] is only dealt with very special automata, namely, with final automata, i.e., automata where the difference between the concepts of state and of process, respectively, disappears. The coalgebraic approach will allow us to develop a proper model theory for process calculi. As first steps in this direction we outline firstly how operations on processes can be generalized in a compatible way to constructions on automata. Secondly, we present a new method for solving recursive process equations. Finally, we discuss that the nondeterminism in CSP can not be modeled based on nondeterministic transition systems usually considered in the coalgebraic literature 5].