Goal:
    A : Type  B : Type  C : Type  R : A → B → C → Type  b : All3 R [] [] []
  ============================
   (∀ (H := CoreTactics.block) (e : NoConfusionHom_All3 A B C R [] [] []
                                      All3_nil b),
      let H0 := CoreTactics.block in
      noConfusionHom_All3_obligation_2 A B C R [] [] [] All3_nil b
        (noConfusionHom_All3_obligation_1 A B C R [] [] [] All3_nil b e) = e)


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