1 Alonzo Church, Ann. Math., 2nd ser., 33, 346-366 (1932), and 34, 839-864 (1933). S. C. Kleene, Ann. Math., 2nd ser., 35, 529-544 (1934). We shall refer to the latter paper as Kleene 1934. 2 Alonzo Church and J. B. Rosser, "Some Properties of Conversion." 3 Explicit formal definitions are given by S. C. Kleene, Amer. Jour. Math., 57, 153173 (1935). This paper, and a second part of it, forthcom...