Extending the Sparkle Core language with object abstraction

Sparkle is a theorem prover specially constructed for the functional programming language Clean. In a pure functional language like Clean the values of the functional variables are constants; variables of functional programs do not change in time. Hence it seems that temporality has no meaning in functional programs. However, in certain cases (e.g. in interactive or distributed programs, or in ones that use IO), we can consider a series of values computed from each other as different states of the same “abstract object”. For this abstract object we can prove temporal properties. In this paper we present a method to describe abstract objects and temporal properties in an extended version of the Sparkle Core language. The creation of such descriptions will be supported by a refactoring tool. The descriptions are completely machine processible, and provide a way to automatize the proof of temporal properties of Clean programs with the extended Sparkle system.