YES
O(n^3)
TRS:
 {
  f(c(s(x), y)) -> f(c(x, s(y))),
  g(c(x, s(y))) -> g(c(s(x), y)),
     g(s(f(x))) -> g(f(x))
 }
 DUP: We consider a non-duplicating system.
  Trs:
   {
    f(c(s(x), y)) -> f(c(x, s(y))),
    g(c(x, s(y))) -> g(c(s(x), y)),
       g(s(f(x))) -> g(f(x))
   }
  Matrix Interpretation:
   Interpretation class: triangular
       [X2]    [1 1 1][X2]   [0]
   [g]([X1]) = [0 0 1][X1] + [0]
       [X0]    [0 0 1][X0]   [0]
   
       [X2]    [1 1 0][X2]   [0]
   [s]([X1]) = [0 0 0][X1] + [0]
       [X0]    [0 0 1][X0]   [1]
   
       [X5]  [X2]    [1 0 1][X5]   [1 1 0][X2]   [0]
   [c]([X4], [X1]) = [0 1 0][X4] + [0 0 1][X1] + [0]
       [X3]  [X0]    [0 0 0][X3]   [0 0 1][X0]   [0]
   
       [X2]    [1 0 0][X2]   [0]
   [f]([X1]) = [0 0 0][X1] + [1]
       [X0]    [0 0 0][X0]   [1]
   
   
   Qed