Goal:
  
  A : Type
  p : A → bool
  x : A
  l : list A
  IHl : forallb p (List.rev l) = forallb p l
  ============================
   (p x && forallb p (List.rev l) = forallb p (List.rev l) && (p x && true))


DEBUG:Going to execute:
rewrite andb_comm andb_true_r
DEBUG LTAC Evaluated term: rev_unit
DEBUG LTAC Evaluated term: rev_unit
DEBUG LTAC Evaluated term: forallb_app
DEBUG LTAC Evaluated term: forallb_app
DEBUG LTAC Evaluated term: IHl
DEBUG LTAC Evaluated term: IHl