Goal:
  
  A : Type
  B : Type
  P : B → A → A → Type
  b0 : B
  bs : list B
  hd : A
  hd' : A
  tl : list A
  p : P b0 hd hd'
  e0 : #|bs| = #|tl|
  b : B
  bs0 : list B
  hd0 : A
  tl0 : list A
  tl' : list A
  b1 : OnOne2All P bs0 tl0 tl'
  ============================
   (∀ e : NoConfusion_OnOne2All A B P
            {|
              pr1 :=
                {|
                  pr1 := b0 :: bs;
                  pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |}
                |};
              pr2 := OnOne2All_hd P b0 bs hd hd' tl p e0
            |}
            {|
              pr1 :=
                {|
                  pr1 := b :: bs0;
                  pr2 := {| pr1 := hd0 :: tl0; pr2 := hd0 :: tl' |}
                |};
              pr2 := OnOne2All_tl P b bs0 hd0 tl0 tl' b1
            |},
      let H := CoreTactics.block in
      noConfusion_OnOne2All_obligation_2 A B P
        {|
          pr1 :=
            {|
              pr1 := b0 :: bs; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |}
            |};
          pr2 := OnOne2All_hd P b0 bs hd hd' tl p e0
        |}
        {|
          pr1 :=
            {|
              pr1 := b :: bs0;
              pr2 := {| pr1 := hd0 :: tl0; pr2 := hd0 :: tl' |}
            |};
          pr2 := OnOne2All_tl P b bs0 hd0 tl0 tl' b1
        |}
        (noConfusion_OnOne2All_obligation_1 A B P
           {|
             pr1 :=
               {|
                 pr1 := b0 :: bs;
                 pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |}
               |};
             pr2 := OnOne2All_hd P b0 bs hd hd' tl p e0
           |}
           {|
             pr1 :=
               {|
                 pr1 := b :: bs0;
                 pr2 := {| pr1 := hd0 :: tl0; pr2 := hd0 :: tl' |}
               |};
             pr2 := OnOne2All_tl P b bs0 hd0 tl0 tl' b1
           |} e) = e)


DEBUG:Going to execute:
CoreTactics.intros_until_block
DEBUG LTAC Evaluated term: (∀ e : NoConfusion_OnOne2All A B P
                                    {|
                                      pr1 :=
                                        {|
                                          pr1 := b0 :: bs;
                                          pr2 :=
                                            {|
                                              pr1 := hd :: tl;
                                              pr2 := hd' :: tl
                                            |}
                                        |};
                                      pr2 :=
                                        OnOne2All_hd P b0 bs hd hd' tl p e0
                                    |}
                                    {|
                                      pr1 :=
                                        {|
                                          pr1 := b :: bs0;
                                          pr2 :=
                                            {|
                                              pr1 := hd0 :: tl0;
                                              pr2 := hd0 :: tl'
                                            |}
                                        |};
                                      pr2 :=
                                        OnOne2All_tl P b bs0 hd0 tl0 tl' b1
                                    |},
                              let H := CoreTactics.block in
                              noConfusion_OnOne2All_obligation_2 A B P
                                {|
                                  pr1 :=
                                    {|
                                      pr1 := b0 :: bs;
                                      pr2 :=
                                        {|
                                          pr1 := hd :: tl; pr2 := hd' :: tl
                                        |}
                                    |};
                                  pr2 := OnOne2All_hd P b0 bs hd hd' tl p e0
                                |}
                                {|
                                  pr1 :=
                                    {|
                                      pr1 := b :: bs0;
                                      pr2 :=
                                        {|
                                          pr1 := hd0 :: tl0;
                                          pr2 := hd0 :: tl'
                                        |}
                                    |};
                                  pr2 := OnOne2All_tl P b bs0 hd0 tl0 tl' b1
                                |}
                                (noConfusion_OnOne2All_obligation_1 A B P
                                   {|
                                     pr1 :=
                                       {|
                                         pr1 := b0 :: bs;
                                         pr2 :=
                                           {|
                                             pr1 := hd :: tl;
                                             pr2 := hd' :: tl
                                           |}
                                       |};
                                     pr2 :=
                                       OnOne2All_hd P b0 bs hd hd' tl p e0
                                   |}
                                   {|
                                     pr1 :=
                                       {|
                                         pr1 := b :: bs0;
                                         pr2 :=
                                           {|
                                             pr1 := hd0 :: tl0;
                                             pr2 := hd0 :: tl'
                                           |}
                                       |};
                                     pr2 :=
                                       OnOne2All_tl P b bs0 hd0 tl0 tl' b1
                                   |} e) = e)