 artificial intelligence: logic and |  Diodorus Cronus |  frame problem |  future contingents |  identity: over time |  logic: action |  logic: combining |  logic: free |  logic: hybrid |  logic: intensional |  logic: modal |  McTaggart, John M. E. |  Ockham [Occam], William |  Prior, Arthur |  temporal parts |  tense and aspect |  time 