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