Zulip Chat Archive
Stream: new members
Topic: Combing specialize's
Aniruddh Agarwal (Jun 26 2020 at 00:28):
Is there a compound form for specialize
, similar to rw
? I have a bunch of statements like
specialize h n,
specialize h' n,
in a proof.
Jalex Stark (Jun 26 2020 at 00:31):
interesting. (i don't think what you ask for exists) can you show the proof?
tactic#specialize
Aniruddh Agarwal (Jun 26 2020 at 00:31):
Here:
example (hu : seq_limit u l) (hw : seq_limit w l)
(h : ∀ n, u n ≤ v n)
(h' : ∀ n, v n ≤ w n) : seq_limit v l :=
begin
intros ε hε,
cases hu ε hε with N hN,
cases hw ε hε with M hM,
use (max N M),
intros n hn,
specialize hN n (le_of_max_le_left hn),
specialize hM n (le_of_max_le_right hn),
rw [abs_le] at *,
specialize h n,
specialize h' n,
split; linarith,
end
Jalex Stark (Jun 26 2020 at 00:32):
what are u
, l
, w
?
Aniruddh Agarwal (Jun 26 2020 at 00:33):
real-valued sequences. you can find a compiling version of this (sans the proof) here: https://github.com/leanprover-community/tutorials/blob/master/src/exercises/05_sequence_limits.lean#L149
u
, v
and w
are sequences and l
is a real number
Aniruddh Agarwal (Jun 26 2020 at 00:35):
I'm just trying to shave a couple of lines off of my proof :)
Aniruddh Agarwal (Jun 26 2020 at 00:44):
Actually, I can do this:
example (hu : seq_limit u l) (hw : seq_limit w l)
(h : ∀ n, u n ≤ v n)
(h' : ∀ n, v n ≤ w n) : seq_limit v l :=
begin
intros ε hε,
cases hu ε hε with N hN,
cases hw ε hε with M hM,
use (max N M),
intros n hn,
specialize hN n (le_of_max_le_left hn),
specialize hM n (le_of_max_le_right hn),
rw abs_le at *,
split; linarith[h n, h' n],
end
Last updated: Dec 20 2023 at 11:08 UTC