(from O. Fissore, I. Gnaedig, and H. Kirchner. Outermost ground termination. In F. Gadducci and U. Montanari, editors, Proceedings of the 4th International WRLA, volume 71 of Electronic Notes in Theoretical Computer Science, Pisa (Italy), September 2002. Elsevier Science Publishers B. V. (North-Holland). ) (VAR x ) (RULES f(g(a)) -> a f(f(x)) -> b g(x) -> f(g(x)) )