Proceedings of the Twenty-Eighth International Joint Conference on Artificial Intelligence (IJCAI-19) On Computational Tractability for Rational Verification Julian Gutierrez1 , Muhammad Najib1 , Giuseppe Perelli2 , Michael Wooldridge1 1Department of Computer Science, University of Oxford, UK 2Department of Informatics, University of Leicester, UK fjulian.gutierrez, mnajib,
[email protected],
[email protected] Abstract theoretic (e.g., Nash) equilibrium. Unlike model checking, rational verification is still in its infancy: the main ideas, Rational verification involves checking which formal models, and reasoning techniques underlying rational temporal logic properties hold of a concur- verification are under development, while current tool sup- rent/multiagent system, under the assumption that port is limited and cannot yet handle systems of industrial agents in the system choose strategies in game the- size [Toumi et al., 2015; Gutierrez et al., 2018a]. oretic equilibrium. Rational verification can be un- derstood as a counterpart of model checking for One key difficulty is that rational verification is computa- multiagent systems, but while model checking can tionally much harder than model checking, because checking be done in polynomial time for some temporal logic equilibrium properties requires quantifying over the strategies specification languages such as CTL, and polyno- available to players in the system. Rational verification is also mial space with LTL specifications, rational ver- different from model checking in the kinds of properties that ification is much more intractable: 2EXPTIME- each technique tries to check: while model checking is inter- any complete with LTL specifications, even when using ested in correctness with respect to possible behaviour of explicit-state system representations.