∀ {Γ : Type u_1} [inst : LinearOrderedCommGroupWithZero Γ] {A : Type u_2} [inst_1 : Ring A] (v : Valuation A Γ)
  [inst_2 : v.IsRankOneDiscrete],
  Subgroup.zpowers (Valuation.IsRankOneDiscrete.generator v) = MonoidWithZeroHom.valueGroup v