The letter written by Robin Gandy to Max Newman in June 1954

Abstract

This chapter presents the letter written by Robin Gandy to Max Newman in June 1954.In this letter, Robin Gandy discussed with Max Newman the possibility of publication of some of Alan Mathison Turing's work that could not be published earlier. According to Robin, Turing considered that his paper on ordinal logics had never received the attention it deserved. The paper shows clearly that statements about ordinals depend very much on the particular formal representation of the ordinals that is used and on the exact form of the rule of transfinite induction. Robin discussed his plans to write a book on the simple theory of types, which would include some of unpublished results of Turning. According to Robin, Turing should have published his proof of the consistency of type theory with axiom of infinity but without extensionality, as it was an important result that was not widely known. In the letter, Robin also discussed about works of Turing on “equivalence of two logical systems,” “Skewes number,” and other topics.