path: root/grudger.pl

% Cooperates until the second has defected, after
% that move defects forever (he does not forgive).
% http://euler.fd.cvut.cz/predmety/game_theory/lecture_repeat.pdf

grudger([], c).
grudger([d|_], d).
grudger([c|Tail], Decision) :- grudger(Tail, Decision).