## Section: Software

### Bedwyr

Participants : Quentin Heath, Dale Miller [correspondant] .

During 2012, Quentin Heath has made the following important improvements to the Bedwyr model checking system.

The concrete syntaxs for Bedwyr and Abella have been unified. Now, both systems can load the definitions and theorems developed in the other system. Eventually, we expect to have our model checker (Bedwyr) and interactive theorem prover (Abella) share theories and proofs.

The documentation, distribution, and testing of Bedwyr were all improved, greatly increasing the usability of this system.

The underlying support for logic has also been increased. In particular, the Bedwyr system contains a

*tabling*mechanism which is capable of remembering past successful proofs (it can even support a finite failure as a successful proof of a negation). The most recent version of Bedwyr allows one to actually program the table in rather sophisticated ways. For example, simple lemmas can be loaded into the table and these lemmas can be used to greatly extend the range of what is tabled (remembered). We are currently examining different trade-offs between different styles of reasoning in the table (backchaining vs forwardchaining).

The work of Heath is being done in the context of the BATT ADJ project funded by Inria.

See also the web page http://slimmer.gforge.inria.fr/bedwyr/ .