Programming Language Elements for Correctness Proofs

Formal methods are not used widely in industrial software development, because the overhead of formally proving program properties is generally not acceptable. In this paper we present an ongoing research project to make the construction of such proofs easier by embedding the proof system into a compiler. Using the introduced new programming language, the programmer writes formal specification first. The specification is to be refined using stepwise refinement which results in a proof. The compiler checks this proof and generates the corresponding program in a traditional programming language. The resulting code automatically fulfills the requirements of the specification. In this paper we present language elements to build specification statements and proofs. We give a short overview on the metaprogramming techniques of the language that support the programmer’s work. Using a formal model we give the semantics of specification statements and refinements. We also prove the soundness of the basic algorithms of the compiler.