 A natural conjecture was thus that lambda-definability coincided extensionally with general recursiveness. Unlike (CT)—which equates an informally characterized class of functions with one possessing a precise mathematical definition—the statement \(\mathbf{GR} = \mathbf{L}\) potentially admits to formal demonstration. Such a demonstration was given by Church (1936b; and in greater detail by Kleene 1936b) providing the first of several extensional equivalence results which Kleene (1952, sec. 62) would eventually cite as evidence of what he proposed to call “Church’s Thesis”.