MAYBE MAYBE TRS: { f(x, a(b(y))) -> f(a(a(b(x))), y), f(a(x), y) -> f(x, a(y)), f(b(x), y) -> f(x, b(y)) } DUP: We consider a non-duplicating system. Trs: { f(x, a(b(y))) -> f(a(a(b(x))), y), f(a(x), y) -> f(x, a(y)), f(b(x), y) -> f(x, b(y)) } Fail