leifmetcalf

4 ms·

1.
by leifmetcalf 17d ago
I especially liked the proof in that book that looks at the action of a group on its Cayley graph to show a subgroup of a free group is free.
2.
by leifmetcalf 4mo ago
This is a trade that is already done by trading businesses. It doesn’t even need to be this explicit; you could for instance dispose one side of a trade to reduce exposure to insiders.
3.
by leifmetcalf 1y ago
Why do we have that E[max_k alg(k)/opt(k)] is equal to max_k E[alg(k)]/opt(k) ?
4.
by leifmetcalf 1y ago
Gemini 2.5 at least replies that it seems unlikely to be false without hallucinating a proof. From its thoughts it gets very close to figuring out that A_4 exists as a subgroup.
5.
by leifmetcalf 1y ago
My mistake, I said unique path when I should have said unique shortest path. Also, there are trivial solutions with odd cycles and complete graphs which must be excluded. (So the answer to the prompt as originally stated is wrong too)
6.
by leifmetcalf 1y ago
Let G be a group of order 3*2^n. Prove there exists a non-complete non-cyclic Cayley graph of G such that there is a unique shortest path between every pair of vertices, or otherwise prove no such graph exists.
7.
by leifmetcalf 2y ago
This seems pretty convincing to me. At the very least, the story that NVDA dropped because the Deepseek announcement reduced expected demand for cpus seems inconsistent with typical market behaviour. I wonder if we’ll see a correction of th
8.
by leifmetcalf 2y ago
I was wrong about this. Case is a macro (a special-cased macro even, defined at https://github.com/elixir-lang/elixir/blob/4def31f8abea5fba4... ), not a function. It works with pipes because in the AST it&#x27
9.
by leifmetcalf 2y ago
Elixir doesn’t even need a special syntax — it gets Haskell’s LambdaCase as a natural consequence of case being just another function, and the pipe operator always chaining by the first argument. Haskell’s >>= is doing something sligh
10.
by leifmetcalf 4y ago
This is according to ‘climate damages compared to market value’.
11.
by leifmetcalf 4y ago
Haskell gets compiled to core ( https://hackage.haskell.org/package/ghc-9.2.1/docs/GHC-Core.... ) which is pretty similar to lambda calculus, but it has some additions like literals, let expressions, and case e
12.
by leifmetcalf 6y ago
Huh. If I move my mouse fast enough I can escape the lock.
13.
by leifmetcalf 6y ago
Back now in NZ
14.
by leifmetcalf 7y ago
Heat pumps are more than 100% efficient
15.
by leifmetcalf 7y ago
Auckland Transport does the same thing
16.
by leifmetcalf 8y ago
I'd be interested to see how effective algae and mosses are at cleaning air, too, since they are so easy to grow and propagate.
17.
by leifmetcalf 8y ago
I just switched from GSuite to https://www.pobox.com . For $20 a year they manage your email address and forward anything sent to it to another account. I have a gmail free account set up to send emails via smtp through pobox, wh
18.
by leifmetcalf 8y ago
With this? http://duriansoftware.com/joe/Optimizing-is-multiple-checks-...
19.
by leifmetcalf 8y ago
I'm a bit confused, how did you implement let, if, else etc.? I don't really know much about the lambda calculus except for what I learned from a short youtube video.
20.
by leifmetcalf 8y ago
Ah, that explains it. The link actually works, though.
21.
by leifmetcalf 8y ago
How does the url http://redacted/ work? I've never seen a url without a tld on the end. Could I register the domain http://foo ?