 Aristotle |  Bolzano, Bernard |  Dedekind, Richard: contributions to the foundations of mathematics |  descriptions |  Frege, Gottlob |  Frege, Gottlob: theorem and foundations for arithmetic |  Gödel, Kurt |  Leibniz, Gottfried Wilhelm |  logic: classical |  logical constructions |  logicism and neologicism |  Principia Mathematica: notation in |  propositional function |  Russell, Bertrand |  Russell’s paradox |  set theory |  Turing, Alan |  type theory |  Whitehead, Alfred North |  Wittgenstein, Ludwig 