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))
  KBO Processor:
   argument filtering:
    pi(s) = [0]
    pi(dfib) = []
    pi(dfib#) = 0
   usable rules:
    
   weight function:
    w0 = 1
    w(dfib) = 1
    w(dfib#) = w(s) = 0
   precedence:
    dfib# ~ dfib ~ s
   problem:
    DPs:
     
    TRS:
     dfib(s(s(x)),y) -> dfib(s(x),dfib(x,y))
   Qed