(VAR x y) (RULES a -> a' h(x,a',y) -> h(x,y,y) h(x,y,a') -> h(x,y,y) g -> f h(f,a,a) -> h(g,a,a) h(g,a,a) -> h(f,a,a) ) (COMMENT from Example 2 of \cite{OO03})