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 usetendstoinstead.
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: May 02 2025 at 03:31 UTC