Abstract

We model the ‘100 prisoners and a lightbulb’ puzzle in an epistemic logic incorporating dynamic operators for the effects of information changing events. Such events include both informative actions, where agents become more informed about the non-changing state of the world, and factual changes, wherein the world and the facts describing it change themselves as well. We specify the underlying nondeterministic protocol and verify its postconditions in a recent extension of the model checker DEMO with factual change. We also present a synchronized version of the riddle, for which there are also other protocols, and we report on efforts to minimize the expected termination of such protocols when assuming random scheduling.