∀ {R : Type u_1} [inst : CommRing R] [inst_1 : ValuativeRel R] {Γ₀ : Type u_3}
  [inst_2 : LinearOrderedCommGroupWithZero Γ₀] [_t : TopologicalSpace R] [IsValuativeTopology R] {v : Valuation R Γ₀}
  [v.Compatible] {r : MonoidWithZeroHom.ValueGroup₀ v}, r ≠ 0 → IsOpen {x | v.restrict x ≤ r}