minlog

Proof assistant based on first order natural deduction calculus

intended to reason about computable functionals, using minimal rather than classical or intuitionistic logic. The main motivation behind MINLOG is to exploit the proofs-as-programs paradigm for program development and program verification. Proofs are in fact treated as first class objects which can be normalized. If a formula is existential then its proof can be used for reading off an instance of it, or changed appropriately for program development by proof transformation. To this end MINLOG is equipped with tools to extract functional programs directly from proof terms. This also applies to non-constructive proofs, using a refined A-translation. The system is supported by automatic proof search and normalization by evaluation as an efficient term rewriting device. Minlog can be used with ProofGeneral, which allows proofs to be edited using emacs and xemacs. This requires the proofgeneral-minlog package to be installed.