∀ {α : Type u_1} {r : SetRel α α} (length : ℕ) (toFun : Fin (length + 1) → α)
  (step : ∀ (i : Fin length), (toFun i.castSucc, toFun i.succ) ∈ r) (length_1 : ℕ) (toFun_1 : Fin (length_1 + 1) → α)
  (step_1 : ∀ (i : Fin length_1), (toFun_1 i.castSucc, toFun_1 i.succ) ∈ r),
  ({ length := length, toFun := toFun, step := step } = { length := length_1, toFun := toFun_1, step := step_1 }) =
    (length = length_1 ∧ toFun ≍ toFun_1)