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