Goal:
  
  A : Type
  B : Type
  C : Type
  R : A → B → C → Type
  b0 : All3 R [] [] []
  x : A
  y : B
  z : C
  l : list A
  l' : list B
  l'' : list C
  r : R x y z
  b : All3 R l l' l''
  ============================
   ({|
      pr1 := {| pr1 := []; pr2 := {| pr1 := []; pr2 := [] |} |}; pr2 := b0
    |} =
    {|
      pr1 :=
        {| pr1 := x :: l; pr2 := {| pr1 := y :: l'; pr2 := z :: l'' |} |};
      pr2 := All3_cons r b
    |}
    → let H := CoreTactics.block in
      NoConfusionHom_All3 A B C R [] [] [] All3_nil b0
      → let H0 := CoreTactics.block in All3_nil = b0)


DEBUG:Going to execute:
DepElim.simplify_one_dep_elim
Level 4: Backtrace:

Tactic failure (level 1).
Level 3: Backtrace:

Tactic failure.
Level 2: Backtrace:

Tactic failure.