English
For any hd ∈ conductorSet χ, conductor χ ≤ conductor((Classical.choose hd.2).conductor).
Русский
Для любого hd ∈ conductorSet χ выполняется: conductor χ ≤ conductor((Classical.choose hd.2).conductor).
LaTeX
$$$\\forall {d}, (d \in \\operatorname{conductorSet}(\\chi)) \Rightarrow \\operatorname{conductor}(\\chi) \le \\operatorname{conductor}((\\text{Classical.choose } hd.2))$$$
Lean4
theorem conductor_le_conductor_mem_conductorSet {d : ℕ} (hd : d ∈ conductorSet χ) :
χ.conductor ≤ (Classical.choose hd.2).conductor :=
by
refine
Nat.sInf_le <|
(mem_conductorSet_iff χ).mpr <|
⟨dvd_trans (conductor_dvd_level _) hd.1, (factorsThrough_conductor (Classical.choose hd.2)).2.choose, ?_⟩
rw [changeLevel_trans _ (conductor_dvd_level _) hd.dvd, ←
(factorsThrough_conductor (Classical.choose hd.2)).2.choose_spec]
exact hd.eq_changeLevel