Goal:
  
  A : Type
  P : list A → A → Type
  Q : list A → list A → A → A → Type
  Γ' : list A
  H : All2_fold Q [] Γ'
  ============================
   (let H := CoreTactics.block in
    let H0 := CoreTactics.block in
    All2_fold (λ (Γ Γ' : list A) (d d' : A), P Γ d × Q Γ Γ' d d') [] Γ')


DEBUG:Going to execute:
needs_generalization id; DepElim.generalize_sig_dest id
Level 2: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := H
of type
ident of type tacvalue

Level 2: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := H
of type
ident of type tacvalue

Level 1: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := H
of type
ident of type tacvalue

Level 1: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := H
of type
ident of type tacvalue