Section: Research Program

Automated theorem proving

Deduction modulo has originally been proposed to solve a problem in automated theorem proving and some of the early work in this area focused on the design of an automated theorem proving method called Resolution modulo, but this method was so complex that it was never implemented. This method was simplified in 2010 [5] and it could then be implemented. This implementation that builds on the iProver effort [36] is called iProver modulo.

iProver modulo gave surprisingly good results [4], so that we use it now to search for proofs in many areas: in the theory of classes—also known as B set theory—, on finite structures, etc. Similar ideas have also been implemented for the tableau method with in particular several extensions of the Zenon automated theorem prover. More precisely, two extensions have been realized: the first one is called SuperZenon  [35] [30] and is an extension to superdeduction (which is a variant of Deduction modulo), and the second one is called ZenonModulo  [28], [29] and is an extension to Deduction modulo. Both extensions have been extensively tested over first-order problems (of the TPTP library), and also provide good results in terms of number of proved problems. In particular, these tools provide good performances in set theory, so that SuperZenon has been successfully applied to verify B proof rules of Atelier B (work in collaboration with Siemens). Similarly, we plan to apply ZenonModulo in the framework of the BWare project to verify B proof obligations coming from the modeling of industrial applications.

More generally, we believe that proof-checking and automated theorem proving have a lot to learn from each other, because a proof is both a static linguistic object justifying the truth of a proposition and a dynamic process of proving this proposition.