Zulip Chat Archive
Stream: Is there code for X?
Topic: Limit of addition of functions
Ashvni Narayanan (Jul 05 2022 at 16:02):
I am looking for a lemma of the form :
example {X : Type*} [topological_space X] [t2_space X] [add_comm_monoid X] [has_continuous_add X]
(f g : ℕ → X) : lim filter.at_top (λ x : ℕ, f x + g x) = lim filter.at_top (λ x : ℕ, f x) + lim filter.at_top (λ x : ℕ, g x) := sorry
Any help is appreciated. Thank you!
Sebastien Gouezel (Jul 05 2022 at 16:05):
Have a look at docs#filter.tendsto.add
Sebastien Gouezel (Jul 05 2022 at 16:06):
The lemma as you wrote it can not be true (what happens if one function is not converging?). In general, don't use lim
, and use tendsto
instead.
Ashvni Narayanan (Jul 05 2022 at 16:08):
Sebastien Gouezel said:
The lemma as you wrote it can not be true (what happens if one function is not converging?). In general, don't use
lim
, and usetendsto
instead.
Thank you! I know this is not true in general, I was looking for a better lemma that has probably already formulated it.
Last updated: Dec 20 2023 at 11:08 UTC