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