Goal:
    A : Type  P : A → Type  Q : A → Type  Hl' : All Q []
  ============================
   (All (λ x : A, P x × Q x) [])


DEBUG:Going to execute:
DepElim.do_intros H; DepElim.generalize_by_eqs H
Level 1: evaluation returns
DepElim.do_intros H; DepElim.generalize_by_eqs H; tac H
where
tac := fun hyp => DepElim.do_case hyp
       where
       id := Hl'
       of type
       constr
of type
tacvalue
H := Hl'
of type
constr of type tacvalue