The consistency of the axiom of choice and of the generalized continuum hypothesis (1938)
Kurt Gudel · 2001
Abstract The method of proof consists in constructing on the basis of the axioms of T a model for which the propositions 1-4 are true. This model, roughly speaking, consists of all “mathematically constructible” sets, where the term “constructible” is to be understood in the semi-intuitionistic sense which excludes impredicative procedures. This means “constructible” sets are defined to be those sets which can be obtained by Russell’s ramified hierarchy of types, if extended to include transfinite orders.