Talk by ACM A.M. Turing Laureate Dana S. Scott during the ACM A.M. Turing Centenary Celebration, June, 2012. Abstract: A very fast development in the early 1930s, following Hilbert's codification of Mathematical Logic, led to the Incompleteness Theorems, Computable Functions, Undecidability Theorems, and the general formulation of recursive Function Theory. The so-called ...