Abstract Data Types Can HaveInequations ¹

Abstract

Abstract. This work proposes a typed functional wide-spectrum language, Funiq, for both programming and specification as an extension of Cardelli-Wegner’s Fun enriched with the fixed-point construction on expressions and inequational refinements (as assertions) for types. The type system of our wide-spectrum Funiq language is shown to be a conservative extension of that of the original Fun and sound with respect to the complete PER semantics for types.