YES
O(n^5)
TRS:
 {f() -> g(),
  c() -> f()}
 DUP: We consider a non-duplicating system.
  Trs:
   {f() -> g(),
    c() -> f()}
  Matrix Interpretation:
   Interpretation class: triangular
         [0]
         [0]
   [g] = [0]
         [0]
         [0]
   
         [3]
         [0]
   [c] = [0]
         [0]
         [0]
   
         [2]
         [0]
   [f] = [0]
         [0]
         [0]
   
   
   Qed