YES

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

Proof:
 DP Processor:
  DPs:
   dfib#(s(s(x)),y) -> dfib#(x,y)
   dfib#(s(s(x)),y) -> dfib#(s(x),dfib(x,y))
  TRS:
   dfib(s(s(x)),y) -> dfib(s(x),dfib(x,y))
  Restore Modifier:
   DPs:
    dfib#(s(s(x)),y) -> dfib#(x,y)
    dfib#(s(s(x)),y) -> dfib#(s(x),dfib(x,y))
   TRS:
    dfib(s(s(x)),y) -> dfib(s(x),dfib(x,y))
   SCC Processor:
    #sccs: 1
    #rules: 2
    #arcs: 4/4
    DPs:
     dfib#(s(s(x)),y) -> dfib#(x,y)
     dfib#(s(s(x)),y) -> dfib#(s(x),dfib(x,y))
    TRS:
     dfib(s(s(x)),y) -> dfib(s(x),dfib(x,y))
    Matrix Interpretation Processor:
     dimension: 1
     interpretation:
      [dfib#](x0, x1) = x0,
      
      [dfib](x0, x1) = 0,
      
      [s](x0) = x0 + 1
     orientation:
      dfib#(s(s(x)),y) = x + 2 >= x = dfib#(x,y)
      
      dfib#(s(s(x)),y) = x + 2 >= x + 1 = dfib#(s(x),dfib(x,y))
      
      dfib(s(s(x)),y) = 0 >= 0 = dfib(s(x),dfib(x,y))
     problem:
      DPs:
       
      TRS:
       dfib(s(s(x)),y) -> dfib(s(x),dfib(x,y))
     Qed