Goal:
    A : Type  P : list A → list A → A → A → Type
  ============================
   (∀ Γ : list A,
      {| pr1 := Γ; pr2 := Γ |} = {| pr1 := []; pr2 := [] |}
      → let H := CoreTactics.block in
        let H0 := CoreTactics.block in
        All_fold (λ (Γ0 : list A) (d : A), P Γ0 Γ0 d d) Γ)


DEBUG:Going to execute:
let H := fresh x in
           intro
           H
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.
Level 2: Backtrace:

The first hypothesis in the goal is not an equality.