Goal:
    A : Type  P : list A → list A → A → A → Type
  ============================
   (∀ e : NoConfusion_All2_fold A P
            {| pr1 := {| pr1 := []; pr2 := [] |}; pr2 := All2_fold_nil P |}
            {| pr1 := {| pr1 := []; pr2 := [] |}; pr2 := All2_fold_nil P |},
      let H := CoreTactics.block in
      noConfusion_All2_fold_obligation_2 A P
        {| pr1 := {| pr1 := []; pr2 := [] |}; pr2 := All2_fold_nil P |}
        {| pr1 := {| pr1 := []; pr2 := [] |}; pr2 := All2_fold_nil P |}
        (noConfusion_All2_fold_obligation_1 A P
           {| pr1 := {| pr1 := []; pr2 := [] |}; pr2 := All2_fold_nil P |}
           {| pr1 := {| pr1 := []; pr2 := [] |}; pr2 := All2_fold_nil P |} e) =
      e)


DEBUG:Going to execute:
intro; CoreTactics.intros_until_block