One Logic to Use Them All

Deductive program veri cation is making fast progress these days. One of the reasons is a tremendous improvement of theorem provers in the last two decades. This includes various kinds of automated theorem provers, such as ATP systems and SMT solvers, and interactive proof assistants. Yet most tools for program veri cation are built around a single theorem prover. Instead, we defend the idea that a collaborative use of several provers is a key to easier and faster veri cation. This paper introduces a logic that is designed to target a wide set of theorem provers. It is an extension of rst-order logic with polymorphism, algebraic data types, recursive de nitions, and inductive predicates. It is implemented in the tool Why3, and has been successfully used in the veri cation of many non-trivial programs.