The Action Graph Model as a Link Between Abstract Relation Algebras and Process Algebraic Speci cations

Relational algebra in the sense of Schr oder and Tarski has been thoroughly studied by mathematicians from the universal algebraic viewpoint and some research has shown many applications of the relational calculus in the elds of graph theory and computer science This paper addresses the eld of process algebraic languages which are used for the speci cation and veri cation of communicating systems The construction of a bridge from process algebra to relational algebra is investigated A process algebraic language is propounded by adding a par allelism operator to the structure of relational algebra its semantics is given by the action graph model The action graph model follows the interpretation of concurrent processes by nite partial orders and technically it is constructed by viewing relation algebras as boolean algebras with operators It establishes a correspondence between relational algebra with parallelism operator and a process algebra which in particular carries an additional combinator playing the r ole of undo