Goal:
  
  A : Type
  P : nat → A → A → Type
  i : nat
  hd : A
  tl : list A
  tl' : list A
  a : OnOne2i P (S i) tl tl'
  i0 : nat
  hd0 : A
  hd' : A
  tl0 : list A
  p : P i0 hd0 hd'
  ============================
   (∀ e : NoConfusion_OnOne2i A P
            {|
              pr1 :=
                {|
                  pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd :: tl' |}
                |};
              pr2 := OnOne2i_tl P i hd tl tl' a
            |}
            {|
              pr1 :=
                {|
                  pr1 := i0;
                  pr2 := {| pr1 := hd0 :: tl0; pr2 := hd' :: tl0 |}
                |};
              pr2 := OnOne2i_hd P i0 hd0 hd' tl0 p
            |},
      let H := CoreTactics.block in
      noConfusion_OnOne2i_obligation_2 A P
        {|
          pr1 :=
            {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd :: tl' |} |};
          pr2 := OnOne2i_tl P i hd tl tl' a
        |}
        {|
          pr1 :=
            {|
              pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd' :: tl0 |}
            |};
          pr2 := OnOne2i_hd P i0 hd0 hd' tl0 p
        |}
        (noConfusion_OnOne2i_obligation_1 A P
           {|
             pr1 :=
               {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd :: tl' |} |};
             pr2 := OnOne2i_tl P i hd tl tl' a
           |}
           {|
             pr1 :=
               {|
                 pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd' :: tl0 |}
               |};
             pr2 := OnOne2i_hd P i0 hd0 hd' tl0 p
           |} e) = e)


DEBUG:Going to execute:
CoreTactics.intros_until_block
DEBUG LTAC Evaluated term: (∀ e : NoConfusion_OnOne2i A P
                                    {|
                                      pr1 :=
                                        {|
                                          pr1 := i;
                                          pr2 :=
                                            {|
                                              pr1 := hd :: tl;
                                              pr2 := hd :: tl'
                                            |}
                                        |};
                                      pr2 := OnOne2i_tl P i hd tl tl' a
                                    |}
                                    {|
                                      pr1 :=
                                        {|
                                          pr1 := i0;
                                          pr2 :=
                                            {|
                                              pr1 := hd0 :: tl0;
                                              pr2 := hd' :: tl0
                                            |}
                                        |};
                                      pr2 := OnOne2i_hd P i0 hd0 hd' tl0 p
                                    |},
                              let H := CoreTactics.block in
                              noConfusion_OnOne2i_obligation_2 A P
                                {|
                                  pr1 :=
                                    {|
                                      pr1 := i;
                                      pr2 :=
                                        {|
                                          pr1 := hd :: tl; pr2 := hd :: tl'
                                        |}
                                    |};
                                  pr2 := OnOne2i_tl P i hd tl tl' a
                                |}
                                {|
                                  pr1 :=
                                    {|
                                      pr1 := i0;
                                      pr2 :=
                                        {|
                                          pr1 := hd0 :: tl0;
                                          pr2 := hd' :: tl0
                                        |}
                                    |};
                                  pr2 := OnOne2i_hd P i0 hd0 hd' tl0 p
                                |}
                                (noConfusion_OnOne2i_obligation_1 A P
                                   {|
                                     pr1 :=
                                       {|
                                         pr1 := i;
                                         pr2 :=
                                           {|
                                             pr1 := hd :: tl;
                                             pr2 := hd :: tl'
                                           |}
                                       |};
                                     pr2 := OnOne2i_tl P i hd tl tl' a
                                   |}
                                   {|
                                     pr1 :=
                                       {|
                                         pr1 := i0;
                                         pr2 :=
                                           {|
                                             pr1 := hd0 :: tl0;
                                             pr2 := hd' :: tl0
                                           |}
                                       |};
                                     pr2 := OnOne2i_hd P i0 hd0 hd' tl0 p
                                   |} e) = e)