A Formalisation of Evolving Algebras

Evolving Algebras is a speciication formalism developed by Y. Gurevich. It is applied in a number of cases, e.g. to deene the semantics of programming languages and protocols. This paper presents a formal deenition of Evolving Algebras with a clear separation between syntax and semantics, leading (among other things) to an elaboration of the join operator. The relation with the formal speciication language COLD is stressed.