∀ (s : Std.Time.Nanosecond.Offset),
  (Std.Time.Internal.UnitVal.cast Std.Time.Duration.ofNanoseconds._proof_1✝
            (Std.Time.Internal.UnitVal.tdiv s 1000000000)).val ≥
        0 ∧
      ↑(Std.Time.Internal.Bounded.LE.byMod s.val 1000000000 Std.Time.Duration.ofNanoseconds._proof_2✝) ≥ 0 ∨
    (Std.Time.Internal.UnitVal.cast Std.Time.Duration.ofNanoseconds._proof_1✝¹
            (Std.Time.Internal.UnitVal.tdiv s 1000000000)).val ≤
        0 ∧
      ↑(Std.Time.Internal.Bounded.LE.byMod s.val 1000000000 Std.Time.Duration.ofNanoseconds._proof_2✝¹) ≤ 0