## Section: New Software and Platforms

### Bedwyr

Participants : Quentin Heath, Dale Miller [correspondant] .

Main web-site: http://slimmer.gforge.inria.fr/bedwyr/ .

Quentin Heath has continued to maintain and enhance this model checking system. In particular, the tabling mechanism has been extended and formalized to a greater extent. The tabling mechanism is now able to use Horn clause lemmas in order to increase the power of the table. For example, given this enhancement it is possible to tell Bedwyr that if a given board position (in some game) has a winning strategy then symmetric versions of that board also have winning strategies. Thus, when a given board position is recognized as winning, then table will understand that all symmetric versions of that board are winning.

Significant energies have also gone into trying to understand how cyclic proofs (recognized using the tabling mechanism) can be turned into certifiable proof evidence. Good results are currently developed for treating bisimulation and non-reachability: in these cases, cyclic proofs are used to supply invariants for induction and co-induction.