Goal:
    A : Type  B : Type  R : nat → A → B → Type  n : nat  b : All2i R n [] []
  ============================
   (let H := CoreTactics.block in
    NoConfusionHom_All2i A B R n [] [] All2i_nil b
    → let H0 := CoreTactics.block in All2i_nil = b)


DEBUG:Going to execute:
needs_generalization id; DepElim.generalize_sig_dest id
Level 4: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := b
of type
constr of type tacvalue

Level 4: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := b
of type
constr of type tacvalue

Level 3: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := b
of type
constr of type tacvalue

Level 3: evaluation returns
(needs_generalization id; DepElim.generalize_sig_dest id) || idtac
where
id := b
of type
constr of type tacvalue