Goal:
    A : Type  B : Type  R : nat → A → B → Type  n : nat
  ============================
   (∀ (H := CoreTactics.block) (e : NoConfusionHom_All2i A B R n [] []
                                      All2i_nil All2i_nil),
      let H0 := CoreTactics.block in
      noConfusionHom_All2i_obligation_2 A B R n [] [] All2i_nil All2i_nil
        (noConfusionHom_All2i_obligation_1 A B R n [] [] All2i_nil All2i_nil
           e) = e)


DEBUG:Going to execute:
match T with
           | context [ CoreTactics.block ] =>
               change T; CoreTactics.intros_until_block
           end