Zulip Chat Archive
Stream: Is there code for X?
Topic: monotone right inverse
Rémy Degenne (Jan 14 2021 at 09:28):
It feels like it should be somewhere, but I cannot find the following statement:
lemma function.right_inverse.monotone {α β} [linear_order α] [partial_order β]
{g : α → β} {g_inv : β → α} (hg_right_inv : function.right_inverse g_inv g)
(hg_mono : monotone g) :
monotone g_inv :=
begin
intros x y hxy,
cases le_iff_lt_or_eq.mp hxy with h_lt h_eq,
{ rw [←hg_right_inv x, ←hg_right_inv y] at h_lt,
exact le_of_lt (monotone.reflect_lt hg_mono h_lt), },
{ rw h_eq, },
end
Heather Macbeth (Jan 14 2021 at 12:45):
Do you know about docs#order_embedding, docs#order_iso? I can't find the result you want in that file, but it seems like it might be its natural home ...
Rémy Degenne (Jan 14 2021 at 12:51):
yes I found order_iso about an hour ago and rewrote my proofs with it, which also made them simpler. Thanks!
Last updated: Dec 20 2023 at 11:08 UTC