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
  tl0 : list A
  tl'0 : list A
  b : OnOne2i P (S i0) tl0 tl'0
  ============================
   (let H := CoreTactics.block in
    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 := hd0 :: tl'0 |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl'0 b
      |}
    → let H0 := CoreTactics.block in
      {|
        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 := hd0 :: tl'0 |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl'0 b
      |})


DEBUG:Going to execute:
match goal with
           | hyp:context [ CoreTactics.block ]
             |- _ =>
                 cbn beta in hyp; eqns_specialize_eqs_block hyp;
                  cbn[eq_rect_r eq_rect] in hyp
           end
Level 2: Backtrace:

No matching clauses for match.

Goals:
  
  A : Type
  P : nat → A → A → Type
  i : nat
  hd : A
  hd' : A
  tl : list A
  p : P i hd hd'
  i0 : nat
  hd0 : A
  hd'0 : A
  tl0 : list A
  p0 : P i0 hd0 hd'0
  ============================
   (let H := CoreTactics.block in
    NoConfusion_OnOne2i A P
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |}
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd'0 :: tl0 |} |};
        pr2 := OnOne2i_hd P i0 hd0 hd'0 tl0 p0
      |}
    → let H0 := CoreTactics.block in
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |} =
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd'0 :: tl0 |} |};
        pr2 := OnOne2i_hd P i0 hd0 hd'0 tl0 p0
      |})

  
  A : Type
  P : nat → A → A → Type
  i : nat
  hd : A
  hd' : A
  tl : list A
  p : P i hd hd'
  i0 : nat
  hd0 : A
  tl0 : list A
  tl' : list A
  b : OnOne2i P (S i0) tl0 tl'
  ============================
   (let H := CoreTactics.block in
    NoConfusion_OnOne2i A P
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |}
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd0 :: tl' |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl' b
      |}
    → let H0 := CoreTactics.block in
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |} =
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd0 :: tl' |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl' b
      |})

  
  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'
  ============================
   (let H := CoreTactics.block in
    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 H0 := CoreTactics.block in
      {|
        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
      |})

  
  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
  tl0 : list A
  tl'0 : list A
  b : OnOne2i P (S i0) tl0 tl'0
  ============================
   (let H := CoreTactics.block in
    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 := hd0 :: tl'0 |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl'0 b
      |}
    → let H0 := CoreTactics.block in
      {|
        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 := hd0 :: tl'0 |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl'0 b
      |})


DEBUG:Going to execute:
DepElim.unblock_dep_elim
Level 2: Backtrace:

No matching clauses for match.

Goals:
  
  A : Type
  P : nat → A → A → Type
  i : nat
  hd : A
  hd' : A
  tl : list A
  p : P i hd hd'
  i0 : nat
  hd0 : A
  hd'0 : A
  tl0 : list A
  p0 : P i0 hd0 hd'0
  ============================
   (let H := CoreTactics.block in
    NoConfusion_OnOne2i A P
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |}
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd'0 :: tl0 |} |};
        pr2 := OnOne2i_hd P i0 hd0 hd'0 tl0 p0
      |}
    → let H0 := CoreTactics.block in
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |} =
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd'0 :: tl0 |} |};
        pr2 := OnOne2i_hd P i0 hd0 hd'0 tl0 p0
      |})

  
  A : Type
  P : nat → A → A → Type
  i : nat
  hd : A
  hd' : A
  tl : list A
  p : P i hd hd'
  i0 : nat
  hd0 : A
  tl0 : list A
  tl' : list A
  b : OnOne2i P (S i0) tl0 tl'
  ============================
   (let H := CoreTactics.block in
    NoConfusion_OnOne2i A P
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |}
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd0 :: tl' |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl' b
      |}
    → let H0 := CoreTactics.block in
      {|
        pr1 := {| pr1 := i; pr2 := {| pr1 := hd :: tl; pr2 := hd' :: tl |} |};
        pr2 := OnOne2i_hd P i hd hd' tl p
      |} =
      {|
        pr1 :=
          {| pr1 := i0; pr2 := {| pr1 := hd0 :: tl0; pr2 := hd0 :: tl' |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl' b
      |})

  
  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'
  ============================
   (let H := CoreTactics.block in
    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 H0 := CoreTactics.block in
      {|
        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
      |})

  
  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
  tl0 : list A
  tl'0 : list A
  b : OnOne2i P (S i0) tl0 tl'0
  ============================
   (let H := CoreTactics.block in
    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 := hd0 :: tl'0 |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl'0 b
      |}
    → let H0 := CoreTactics.block in
      {|
        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 := hd0 :: tl'0 |} |};
        pr2 := OnOne2i_tl P i0 hd0 tl0 tl'0 b
      |})


DEBUG:Going to execute:
match goal with
           | |- let _ := CoreTactics.block in ?T =>
                 match T with
                 | context [ CoreTactics.block ] =>
                     change T; CoreTactics.intros_until_block
                 end
           | _ => CoreTactics.unblock_goal
           end