YES

TRS:

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

linear polynomial interpretations on N:

  dfib_A(x1,x2) = 1
  dfib#_A(x1,x2) = 1
  s_A(x1) = x1 + 1
  s#_A(x1) = x1

precedence:

  dfib > s