In your review of Fraenkel & Rahat, Infinite cyclic impartial games, Theor. Comput. Sci. 252, No.1-2, 13--22(2001), the reviewer has failed to understand the import of the Sprague-Grundy theory and the late Cedric Smith's infinite extension thereof. In the present context, in the comparatively uninteresting case of play with a single token on a graph with a single component, it would indeed suffice to classify the positions as N-positions, O-positions or P-positions. But as soon as there are two or more N-positions we cannot decide the outcome. We need the simple but powerful theorem that the nim-value (Sprague-Grundy value) of the sum (i.e., disjunctive compound) of games is the nim-sum of their nim-values. Every impartial game is equivalent to playing Nim -- but we need to know how many beans there are in each heap. Mit bestem Gr"usse, Richard K. Guy.