 artificial intelligence: logic and |  computability and complexity |  Curry’s paradox |  Fitch’s paradox of knowability |  Gödel, Kurt |  Gödel, Kurt: incompleteness theorems |  Hilbert, David: program in the foundations of mathematics |  logic, history of: modal logic |  logic: classical |  logic: epistemic |  logic: intuitionistic |  logic: modal |  logic: relevance |  mathematics: constructive |  model theory |  possible worlds |  Principia Mathematica |  proof theory: development of |  Quine, Willard Van Orman |  self-reference |  set theory: independence and large cardinals |  Turing, Alan 