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