Goal:
  
  A : Type
  B : Type
  C : Type
  P : nat → A → B → Type
  Q : B → C → Type
  R : nat → A → C → Type
  S : nat → A → C → Type
  n : nat
  c1' : nat
  x : A
  y : C
  l : list A
  r : list C
  r0 : R c1' x y
  c : All2i R (Datatypes.S c1') l r
  ============================
   ({| pr1 := n; pr2 := {| pr1 := []; pr2 := [] |} |} =
    {| pr1 := c1'; pr2 := {| pr1 := x :: l; pr2 := y :: r |} |}
    → let H := CoreTactics.block in
      (∀ (n : nat) (x : A) (y : B) (z : C),
         P n x y → Q y z → R n x z → S n x z)
      → let H0 := CoreTactics.block in All2i S n [] [])


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

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

Tactic failure.
Level 0: Backtrace:

Tactic failure.