The Evolution of Type Theory until the 1940s -- Prehistory -- Type theory in Principia Mathematica -- Deramification -- Propositions as Types, Pure Type Systems, AUTOMATH -- Propositions as Types and Pure Type Systems -- The pre-PAT RTT and STT in PAT-style -- A Correspondence between RTT and the system Nuprl -- Automath -- Extensions of Pure Type Systems -- Pure Type Systems with definitions -…