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:
CoreTactics.intros_until_block
DEBUG LTAC Evaluated term: (∀ 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)