Zulip Chat Archive
Stream: Is there code for X?
Topic: Criterion for `set.finite` from finsets
Heather Macbeth (Jan 05 2022 at 20:08):
Looking for this lemma, or a slick proof!
import data.set.finite
example {β : Type*} {n : ℕ} (H : ∀ (s : finset β), s.card ≤ n) :
(set.univ : set β).finite :=
sorry
Adam Topaz (Jan 05 2022 at 20:13):
import data.set.finite
example {β : Type*} {n : ℕ} (H : ∀ (s : finset β), s.card ≤ n) :
(set.univ : set β).finite :=
begin
haveI : fintype β := fintype_of_finset_card_le n H,
exact set.finite_univ
end
Heather Macbeth (Jan 05 2022 at 20:13):
Nice, thanks!
Last updated: Dec 20 2023 at 11:08 UTC