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


DEBUG:Going to execute:
inv Allx
DEBUG LTAC Evaluated term: rev_app_distr
DEBUG LTAC Evaluated term: rev_app_distr
DEBUG LTAC Evaluated term: All_app