robinhouston

User cachecrab on Twitter noticed that Google has a rather unusual interpretation of the query “20% of £1k”.

Spotted in The American Mathematical Monthly, Vol. 99, No. 2 (Feb., 1992)

RE: @arXiv_csLO_bot@mastoxiv.page

It looks as though one of my favourite problems has been solved!

It's related to both Petri nets and linear logic.

BVAS are more general than VAS – which are more or less the same as Petri nets. The reachability problem for VAS was previously known to be decidable, but with outrageous complexity (Ackermann-complete), so the reachability problem for BVAS must be at least as hard as that. But this work doesn't answer the question of just how much harder it is.

Surely someone is missing something here: the woven artefact is clearly a cuboctahedron, and I don't think any wasps make cuboctahedral nests.

I guess we’re all getting a little tired of talking about this sort of thing, but I think this is the most impressive example yet of an LLM-generated solution to a long-open mathematical problem:

https://www.erdosproblems.com/forum/thread/1196

Jared Lichtman, a mathematician who has spent (in his words) “many years” working on the problem himself, describes the proof as “a remarkable artifact […] from The Book”.

(See also https://x.com/jdlichtman/status/2044298382852927894 if you do 𝕏.)

I didn’t realise this article was out already! Featuring some computations and diagrams by me (which, to my great excitement, Don Knuth emailed me about when he heard of them).

_On Max Bill’s gelbes feld_ by Barry Cipra.

https://www.ams.org/journals/notices/202605/noti3334/noti3334.html

I can’t find a PDF of just that article. Maybe the Notices don’t do that any more? But here is the whole issue, if you want it formatted more nicely: https://www.ams.org/journals/notices/202605/202605FullIssue-optimized.pdf

There’s a fun paper showing that you can define all elementary functions using just two primitive operations: the constant 1, and the binary function eml(x, y) := e^x - log(y).

https://arxiv.org/abs/2603.21852

That’s a neat little result, which makes for some fun games.

What’s the simplest expression you can find that evaluates to your favourite constant?

The best I have found for 2 is:

eml(1, eml(eml(eml(1, eml(eml(1, eml(1, eml(1, 1))), 1)), eml(1, 1)), 1))

RE: @henryseg@mathstodon.xyz

This is now my favourite physical object.

I want to know the relative popularity of the Platonic solids, but a Mathstodon poll can have at most four options.

I thought Peter Selinger was on here, but I can't find him. Has he left us?

Just looking at this interesting new paper https://arxiv.org/abs/2604.20964 which does cite Mathstodon posts by @pieter@mathstodon.xyz.

(@christianp@mathstodon.xyz first citation of Mathstodon in a paper, or have there been others?)