Model Checking GDL through MOCHA: A Case Study

The Game Description Language (GDL) is a special purpose declarative language for defining games. GDL is used in the AAAI General Game Playing Competition, which tests the ability of computer programs to play games in general, rather than just to play a specific game. Software participants in the competition are provided with a game specified in GDL, and then required to play this game, interpreting the GDL specification for themselves in order to determine the rules of the game. However, not all GDL specifications correspond to games, let alone meaningful, non-trivial games. We address the problem of verifying that games specified in GDL satisfy appropriate conditions, defining not just games, but meaningful games; we refer to these as playability conditions. Our approach is based on model checking formulae of Alternating-time Temporal Logic (ATL) over GDL specifications. Following an introduction to GDL and ATL, we present GDL2RML, a tool enabling model checking ATL formulae over GDL specifications using MOCHA – an ATL model checker. We illustrate the approach by a case study with experimental results.