State-based extension of casl

Abstract

A state-based extension of the algebraic specification language CASL is presented. It permits the specification of the static part of a complex dynamic system by means of CASL and the dynamic part by means of the facilities described in the paper. The dynamic system is defined as possessing a number of states and a number of operations (procedures) for transforming one state into another. Each state pos- sesses one and the same static part specified by CASL and a varying part specified by additional tools. The varying part includes dynamic sorts/functions/predicates and dependent functions/predicates. The dependent functions/predicates are specified by formulae using the names of the dynamic functions/predicates so that each time one of the last ones is updated the corresponding former ones are also updated. The updates of the dynamic entities are produced by procedures which are specified by means of preconditions, postconditions, and dynamic equations.