YES

Problem:
 dfib(s(s(x)),y) -> dfib(s(x),dfib(x,y))

Proof:
 Matrix Interpretation Processor: dim=1
  
  interpretation:
   [dfib](x0, x1) = 4x0 + x1 + 6,
   
   [s](x0) = 2x0 + 2
  orientation:
   dfib(s(s(x)),y) = 16x + y + 30 >= 12x + y + 20 = dfib(s(x),dfib(x,y))
  problem:
   
  Qed