Sentence:  After all, when Paul Cohen sent his proof of the undecidability of the <WSD>continuum hypothesis</WSD> (which Badiou considers an “event”) to Kurt Gödel in 1963, Gödel wrote back that “reading your proof had a similarly pleasant effect on me as seeing a good play." 
Meaning of the word marked with <WSD> tags:  The hypothesis which states that any infinite subset of <big>ℝ</big> must have the cardinality of either the set of natural numbers or of <big>ℝ</big> itself.