Zulip Chat Archive
Stream: Is there code for X?
Topic: Nontrivial term of nontrivial type
Oliver Nash (Jun 27 2023 at 18:46):
Is this really missing:
@[to_additive]
lemma exists_ne_one (G : Type _) [Group G] [Nontrivial G] : ∃ (g : G), g ≠ 1 := by
obtain ⟨x, y, h⟩ := exists_pair_ne G
exact ⟨x / y, Iff.mpr div_ne_one h⟩
Johan Commelin (Jun 27 2023 at 18:48):
I think that for every x
, you should be able to get a y
that is unequal to it.
Johan Commelin (Jun 27 2023 at 18:49):
That lemma should exist, and it doesn't need algebraic structure.
Sebastien Gouezel (Jun 27 2023 at 18:49):
Oliver Nash (Jun 27 2023 at 18:52):
Right, thanks!
Last updated: Dec 20 2023 at 11:08 UTC