“…To see that the missing “ y 's” in the original definition of diagonal payoff security given in Reny (1999) are needed, we exhibit a game, let us call it , that satisfies the (pre‐correction) hypotheses of Reny's Corollary 4.3 but does not possess a symmetric pure strategy Nash equilibrium. This game is due to Ewerhart (2022). Consider the two‐person game on the unit square in which a player's payoff, , when he chooses x , is x if the other player chooses but is if the other player chooses .…”