Abstract

The main aim of the present paper is to show, by means of a dialogical study, that the notion of judgemental equality of Constructive Type Theory, which in this theory furnishes the criterion of identity of a type, can be understood from the game-theoretical point of view as the result of a specific form of dialogical interaction governed by the development rule known as formal rule or Socratic rule, which prescribes the use of copy-cat moves. It will be shown, as an example, how to develop the core of a winning strategy for Per Martin-Löf’s demonstration of the Axiom of Choice, who based his proof in the judgemental equality between the function in the antecedent and the function occurring in the consequent of the axiom.