Zulip Chat Archive
Stream: general
Topic: proposed lemmas for mathlib
Scott Morrison (Oct 23 2019 at 05:00):
I'd like to add
lemma min_fac_le_div {n : ℕ} (pos : 0 < n) (np : ¬ prime n) : min_fac n ≤ n / min_fac n := ...
to mathlib.
I have an (almost-surely-pessimal) proof, so I'm not asking about that for now, just asking about suitability for mathlib.
Scott Morrison (Oct 23 2019 at 05:00):
One could make an iff
version too.
Johan Commelin (Oct 23 2019 at 05:45):
Seems legit
Reid Barton (Oct 23 2019 at 11:17):
What's the iff version?
Reid Barton (Oct 23 2019 at 11:18):
I hope your proof begins apply min_fac_le_of_dvd,
Johan Commelin (Oct 23 2019 at 11:28):
I guess : ¬ prime n \iff min_fac n ≤ n / min_fac n
Reid Barton (Oct 24 2019 at 01:07):
Oh that makes sense. I was imaging something like "p is the minimum factor of n if and only if ..." and got stuck.
Last updated: Dec 20 2023 at 11:08 UTC