YES(?,O(n^1))
TRS:
 {f f x -> g f x,
  g g x -> f x}
 DUP: We consider a non-duplicating system.
  Trs:
   {f f x -> g f x,
    g g x -> f x}
  Natural interpretation:
   Strict:
    {f f x -> g f x,
     g g x -> f x}
   Weak:
    {}
   Interpretation class: stronglylinear
   [g](X0) = + 1*X0 + 4
   [f](X0) = + 1*X0 + 6
   
   Qed