Goal:
  
  A : Type
  P : list A → A → Type
  d : A
  Γ : list A
  a : All_fold P Γ
  p : P Γ d
  ============================
   (eq_refl = eq_refl)


DEBUG:Going to execute:
simpl; DepElim.hnf_eq; DepElim.rewrite_refl_id