English
For any index type ι and f : ι → Ordinal, the infimum cardinal of the complement of the range is bounded by the lifted cardinal of ι.
Русский
Для любого индекса ι и f: ι → Ordinal нижняя граница дополнения множества range f ограничена взведенной кардинальностью ι.
LaTeX
$$$$ (\\operatorname{sInf}(\\operatorname{range}(f))^{c}).\\operatorname{card} \\le \\operatorname{lift}(\\#ι) $$$$
Lean4
theorem card_sInf_range_compl_le_lift {ι : Type u} (f : ι → Ordinal.{max u v}) :
(sInf (range f)ᶜ).card ≤ Cardinal.lift.{v} #ι :=
by
rw [← Cardinal.lift_le.{max u v + 1}, Cardinal.lift_lift]
apply (lift_card_sInf_compl_le _).trans
rw [← Cardinal.lift_id'.{u, max u v + 1} #(range _)]
exact mk_range_le_lift