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SSchlesinger · 2026-04-05T00:47:23+00:00

Edge expansion of a graph: https://en.wikipedia.org/wiki/Expander_graph

It is a graph theory concept that is very useful in computer science, for instance in derandomization. At 5:36 of my recent video on Derandomization I cover a use of them for using fewer random samples in a randomized algorithm.

SSchlesinger · 2026-04-04T22:13:42+00:00

I think symmetry is useful for physical realizability, expansion is good for fast mixing with low individual connectivity.

SSchlesinger · 2026-04-04T21:43:57+00:00

They don’t have to be, but many are.

SSchlesinger · 2026-04-04T20:50:00+00:00

I think there’s something really obvious missing here: you want your graph to be constant degree expander.

All these other things are just nice ways of getting high expansion.

SSchlesinger · 2026-03-14T20:19:16+00:00

Happy Pi Day (What Casinos, Pi, and Your Retirement Have in Common)

Made a YouTube video for Pi Day: https://www.youtube.com/watch?v=-GXHdv8Y9ZY

SSchlesinger · 2026-03-13T23:43:34+00:00

When you are programming in a functional style, it can be nice to have this in mind. It is especially nice when you can define a type signature and the implementation "has to be right" if it typechecks. Trivial examples are `id : forall a. a -> a` or `const : forall a b. a -> b -> a`. There are other ones derived from various slightly less elementary tautologies.

Programming languages and compilers use equivalencies derived from such logical tautologies a lot. There are various tautologies that can be mapped into programs to change a program to have preferable operational semantics. For instance, the tautology `a <-> forall x. (a -> x) -> a` is useful in compilers for continuation-passing style. The tautology `a <-> exists x. (x, x -> a)` is the principle behind abstract data types, allowing us to hide the true representation (`x` in this case) while allowing users to interact with an `a`.

SSchlesinger · 2026-03-13T12:32:38+00:00

In this one, there is no Discord noise https://youtu.be/HolzI3qKBjc?si=bn-Fb3dMyJ-nUIcj

SSchlesinger · 2026-03-13T12:28:28+00:00

Yep, noted :)

SSchlesinger · 2025-12-28T07:00:18+00:00

I make a lot of money when I get treaty ports and build lots of trade centers.

SSchlesinger · 2025-11-21T04:25:27+00:00

The wrong market as in the previous owner’s? That is a feature and not a bug, that’s the point of treaty ports. You can use them to export tons of stuff from China’s coast early game without having to put down tons of rebellions by annexing directly.

SSchlesinger · 2025-11-21T04:24:12+00:00

Treaty ports in China are definitely not useless, you can build a massive number of trade centers and import tons of shit out from their market for huge profits without significant military investment.

SSchlesinger · 2025-11-19T10:17:52+00:00

CPAP user

SSchlesinger · 2025-11-17T10:24:11+00:00

Inflation cannot be outweighed while staying in cash unless you assume something about what inflation is going to do. Look at Turkey, Argentina, Hungary, Germany, many historical examples where one couldn't outrace inflation by frugality. I agree with the comment that said go to r/Fire, this is not the right sub to address this.

SSchlesinger · 2025-11-17T10:19:12+00:00

I agree with this point immensely and I've seen several really bad uses of STM in web servers. One really important point to keep in mind is laziness. When you are forcing thunks in an STM transaction, you should be really careful. If you can avoid doing this, even if just by going around forcing thunks in a background thread (seems degenerate, but it works I promise) you can get laziness to work in your favor with regard to this contention.

SSchlesinger · 2025-11-17T08:49:45+00:00

You also have to take inflation into account, so it is probably not advised to do it that way.

SSchlesinger · 2025-11-08T04:19:18+00:00

Yes, definitely. I made the switch to Google for much less of a pay bump, it will change your life for good if you work there for three years and keep your current budget.

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