Program proving using intermediate verification languages (IVLs) like boogie and why3.

A program verifier is a complex piece of software. To deal with this complexity, a standard architecture of a modern program verifier consists of two basic parts: a front end and a back end, separated by an intermediate verification language (IVL). The separation of concerns obtained by this architecture is analogous to that in compilers: the front end is concerned with breaking down the semantics of given source-language programs into the more primitive operations of the intermediate language, and the back end is concerned with encoding the meaning of the intermediate program as efficient theorem-prover input. Two prevalent IVLs today are Boogie~2 and Why3. In this invited talk, I will give a tour of the Boogie language. Through a set of examples, I will illustrate how a verifier may translate common source-program features into an IVL. A verification engine for the IVL is then applied to perform the actual verification. In this way, you can obtain a program verifier for your own language by building a new front end and reusing an existing verification engine.