Zulip Chat Archive
Stream: Is there code for X?
Topic: AlgEquiv_invFun_apply
Bolton Bailey (Oct 20 2023 at 13:44):
Do we have this lemma?
lemma AlgEquiv_invFun_apply {R α β : Type} [CommSemiring R] [Semiring α] [Semiring β] [Algebra R α] [Algebra R β]
(e : α ≃ₐ[R] β) (x : α) : x = (e).toEquiv.invFun ((e) x) := by
rw [AlgEquiv.toEquiv_eq_coe, Equiv.invFun_as_coe, @Equiv.eq_symm_apply]
exact rfl
Bolton Bailey (Oct 20 2023 at 13:51):
(and more importantly, can rw_search
prove it?)
Eric Rodriguez (Oct 20 2023 at 14:04):
this should be defeq to e.symm $ e x = x
no?
Eric Wieser (Oct 20 2023 at 15:35):
invFun should never appear in any lemma statement other than the one that eliminates it
Last updated: Dec 20 2023 at 11:08 UTC