B vs. Coq to prove a Garbage Collector

This paper presents a comparison between two formal methods : the B method and the Coq proof assistant on their usability in an industrial context. Those methods have been used to formalise a garbage collector algorithm and prove its safety property. They are compared on two aspects : formalisation and proof. At each step, the two models are compared in terms of readability, easiness of proof and maintainability. Metrics on both development are presented.