MAYBE MAYBE TRS: { plus(x, 0()) -> x, times(x, plus(y, 1())) -> plus(times(x, plus(y, times(1(), 0()))), x), times(x, 1()) -> x, times(x, 0()) -> 0() } DUP: We consider a duplicating system. Trs: { plus(x, 0()) -> x, times(x, plus(y, 1())) -> plus(times(x, plus(y, times(1(), 0()))), x), times(x, 1()) -> x, times(x, 0()) -> 0() } Fail