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The lattice of sets of natural numbers is rich (2021) (jdh.hamkins.org)
scythmic_waves 18 minutes ago [-]
> The power set lattice (P(N)) of all sets of natural numbers, not to scale, some sets omitted...
munchler 3 hours ago [-]
What a beautiful illustration. It makes intuitive the very abstract concepts discussed in the text. It’s fun to zoom in and browse around the structure.
michael0church 3 hours ago [-]
It’s also genuinely surprising. We’re used to thinking of the countable as the small infinity, which it is, and yet a structure we feel like we can visualize contains so much complexity.

There is also, weirdly, a way in which massive finite numbers like TREE(3) “feel” larger than N, and large countable infinities “feel” larger than w_1, even though the opposite is clearly true.

voidmain 3 hours ago [-]
The visualization is of the power set, which is uncountable.
michael0church 3 hours ago [-]
Right. But because it’s the smallest structure of its type (speaking loosely) it feels like something we should have a grasp on, even though it contains more complexity than we could ever describe or compute with (since both of those are countable.)
zaebal 3 hours ago [-]
TREE(3) is unimaginably small, compared to ω
tromp 2 hours ago [-]
TREE(3) is also unimaginably tiny compared to the normal form size of (λa.aaa(λbλcλdλe.ebbbcde)aaaa)(λfλx.f(fx)) [1].

[1] https://wiki.bbchallenge.org/wiki/Lambda_Calculus#Champions

zygentoma 2 hours ago [-]
Well, any natural number is unimaginably small, compared to ω …
flobosg 4 hours ago [-]
(2021)
genxy 1 hours ago [-]
math is timeless
gregw2 3 hours ago [-]
What a great visualization!

Now can your favorite LLM make me a similar one for the Real #s?

stavros 3 hours ago [-]
Why can't yours?
MarkusQ 14 minutes ago [-]
Nope.
2 hours ago [-]
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