MAYBE
Time: 0.003690
TRS:
 {f(f(x, y, a()), z, w) -> f(z, w, f(y, x, z))}
 DP:
  DP:
   {f#(f(x, y, a()), z, w) -> f#(z, w, f(y, x, z)),
    f#(f(x, y, a()), z, w) -> f#(y, x, z)}
  TRS:
  {f(f(x, y, a()), z, w) -> f(z, w, f(y, x, z))}
  UR:
   {f(f(x, y, a()), z, w) -> f(z, w, f(y, x, z)),
                  b(v, u) -> v,
                  b(v, u) -> u}
   EDG:
    {(f#(f(x, y, a()), z, w) -> f#(z, w, f(y, x, z)), f#(f(x, y, a()), z, w) -> f#(y, x, z))
     (f#(f(x, y, a()), z, w) -> f#(z, w, f(y, x, z)), f#(f(x, y, a()), z, w) -> f#(z, w, f(y, x, z)))
     (f#(f(x, y, a()), z, w) -> f#(y, x, z), f#(f(x, y, a()), z, w) -> f#(z, w, f(y, x, z)))
     (f#(f(x, y, a()), z, w) -> f#(y, x, z), f#(f(x, y, a()), z, w) -> f#(y, x, z))}
    STATUS:
     arrows: 0.000000
     SCCS (1):
      Scc:
       {f#(f(x, y, a()), z, w) -> f#(z, w, f(y, x, z)),
        f#(f(x, y, a()), z, w) -> f#(y, x, z)}
      
      SCC (2):
       Strict:
        {f#(f(x, y, a()), z, w) -> f#(z, w, f(y, x, z)),
         f#(f(x, y, a()), z, w) -> f#(y, x, z)}
       Weak:
       {f(f(x, y, a()), z, w) -> f(z, w, f(y, x, z))}
       Fail