(VAR x y ) (RULES cond1(true, x, y) -> cond2(gr(x, y), x, y) cond2(true, x, y) -> cond1(neq(x, 0), y, y) cond2(false, x, y) -> cond1(neq(x, 0), p(x), y) gr(0, x) -> false gr(s(x), 0) -> true gr(s(x), s(y)) -> gr(x, y) neq(0, 0) -> false neq(0, s(x)) -> true neq(s(x), 0) -> true neq(s(x), s(y)) -> neq(x, y) p(0) -> 0 p(s(x)) -> x )