MAYBE
TRS:
 {f(x, s(s(y))) -> f(y, x),
     f(s(x), y) -> f(x, s(s(x)))}
 DP:
  Strict:
   {f#(x, s(s(y))) -> f#(y, x),
       f#(s(x), y) -> f#(x, s(s(x)))}
  Weak:
  {f(x, s(s(y))) -> f(y, x),
      f(s(x), y) -> f(x, s(s(x)))}
  EDG:
   {(f#(s(x), y) -> f#(x, s(s(x))), f#(s(x), y) -> f#(x, s(s(x))))
    (f#(s(x), y) -> f#(x, s(s(x))), f#(x, s(s(y))) -> f#(y, x))
    (f#(x, s(s(y))) -> f#(y, x), f#(x, s(s(y))) -> f#(y, x))
    (f#(x, s(s(y))) -> f#(y, x), f#(s(x), y) -> f#(x, s(s(x))))}
   SCCS:
    Scc:
     {f#(x, s(s(y))) -> f#(y, x),
         f#(s(x), y) -> f#(x, s(s(x)))}
    SCC:
     Strict:
      {f#(x, s(s(y))) -> f#(y, x),
          f#(s(x), y) -> f#(x, s(s(x)))}
     Weak:
     {f(x, s(s(y))) -> f(y, x),
         f(s(x), y) -> f(x, s(s(x)))}
     Fail