Goal:
  
  A : Type
  P : A → Prop
  Q : A → Prop
  p : A → bool
  Hp : ∀ x : A, Q x → reflect (P x) (p x)
  HP : Forall P []
  ============================
   (let H := CoreTactics.block in
    let H0 := CoreTactics.block in forallb p [] = true)


DEBUG:Going to execute:
progress (autounfold with equations in e; simpl in e)
Level 1: evaluation returns
repeat progress (autounfold with equations in e; simpl in e)
where
e := HP
of type
ident of type tacvalue

Level 1: evaluation returns
repeat progress (autounfold with equations in e; simpl in e)
where
e := HP
of type
ident of type tacvalue