Sensing and revision in a modal logic of belief and action

International audienceWe propose a modal logic of belief and actions, where action might be nondeterministic, and there might be misperception. The agent must be able to revise his beliefs, because (contrarily to knowledge) observations might be inconsistent with his beliefs. We propose a new solution in terms of successor state axioms, which does not resort to orderings of plausibility. Our solution allows for regression in the case of deterministic actions