∀ {n : ℕ},
  (Std.Time.Second.Offset.ofInt ↑n).val ≥ 0 ∧ ↑⟨0, Std.Time.instInhabitedDuration._proof_1⟩ ≥ 0 ∨
    (Std.Time.Second.Offset.ofInt ↑n).val ≤ 0 ∧ ↑⟨0, Std.Time.instInhabitedDuration._proof_1⟩ ≤ 0