Goal:
  
  A : Type
  P : A → Type
  x : A
  l : list A
  IHl : All P l → All P (List.rev l)
  ============================
   (All P (l ++ [x]) → All P (x :: List.rev l))


DEBUG:Going to execute:
intros X
DEBUG LTAC Evaluated term: rev_app_distr
DEBUG LTAC Evaluated term: rev_app_distr