McCarthy variations in a modal key Original Research Article

We take a fresh look at some major strands in John McCarthyʹs work from a logicianʹs perspective. First, we re-analyze circumscription in dynamic logics of belief change under hard and soft information. Next, we re-analyze the regression method in the Situation Calculus in terms of update axioms for dynamic–epistemic temporal logics. Finally, we draw some general methodological comparisons between ‘Logical AI’ and practices in modal logic, pointing at some creative tensions.