∀ {Γ : Type u_1} {R : Type u_3} [inst : LinearOrder Γ] [inst_1 : AddCommMonoid Γ] [inst_2 : IsOrderedCancelAddMonoid Γ]
  [inst_3 : CommRing R] (x : (HahnSeries Γ R)ˣ), (x ∈ HahnSeries.orderTopSubOnePos Γ R) = (0 < (↑x - 1).orderTop)