English
δ is independent of presentation, hence δ equals δ on any two presentations Q with P and P'.
Русский
δ независим от презентации; δ совпадает на любом двух представлениях Q с P и P'.
LaTeX
$$$δ Q P = δ Q P'$$$
Lean4
theorem uniformContinuous_coeff {uK : UniformSpace K} (d : ℤ) : UniformContinuous fun f : K⸨X⸩ ↦ f.coeff d :=
by
refine uniformContinuous_iff_eventually.mpr fun S hS ↦ eventually_iff_exists_mem.mpr ?_
let γ : (ℤᵐ⁰)ˣ := Units.mk0 (exp (-(d + 1))) WithZero.coe_ne_zero
use {P | Valued.v (P.snd - P.fst) < ↑γ}
refine ⟨(Valued.hasBasis_uniformity K⸨X⸩ ℤᵐ⁰).mem_of_mem (by tauto), fun P hP ↦ ?_⟩
rw [eq_coeff_of_valuation_sub_lt K (le_of_lt hP) (lt_add_one _)]
exact mem_uniformity_of_eq hS rfl