 The name “Proof Interpretation” for the explanation that Heyting published in the 1930s and later seems to have made its first appearance in print only in 1973, in papers by van Dalen and Kleene, presented at the same conference (van Dalen 1973a; Kleene 1973). Heyting himself spoke simply of the “interpretation” (1958A: 107; 1974: 87) or “the intuitionistic interpretation” (1958A: 110) of logic.