Yes I've had some wine tonight, why?

I think this statement

"For any epsilon > 0 there exists a delta > 0 such that if x and x' are adjacent databases than |f(x)-f(x')| satisfies epsilon-delta DP"

This is, actually, if you think about it, a profound and true statement about differential privacy

Epsilon delta argument but in the sense of differential privacy

Also if you do Lean stuff and are in the area on any given Sunday, reach out! We would like to hear you talk about your work!

Would you like to send me an email? Well boy do I have a shiny new email for you

markus@lean.nyc

This is, by all metrics, a gigantic flex

If I were to gamble, by the way, I'd say this feature is not going to be added to Iris-Rocq

Iris-Lean is now based on ordered resource algebras thanks to typeclasses 😎

One more dead fork. Next up transfinite Iris.

https://leanprover.zulipchat.com/#narrow/channel/490604-iris-lean/topic/Upcoming.20change.3A.20Iris-Lean.20will.20be.20based.20on.20ORAs/with/631668157

Doing some formalization this morning and I am depending on a lemma I PR'd into mathlib last year 😇 feelsgoodman

How many fundamental theorems are just universal properties, anyways

Looking at this page and like, come on ya'll is anyone really out here using "the fundamental theorem of equivalence relations" my god

https://en.wikipedia.org/wiki/List_of_theorems_called_fundamental

I am going to go on a walk and try to convince myself not to buy $200 of t shirts

For $200 would I do this

Yes

If you wear a Jane street t shirt

A) Why

B) If I give you a "Markus de Medeiros is hot and funny" t shirt and will you also wear it for free I'm maybe not even kidding about this

Let me just write this down here because I seem to get it backwards every 20 minutes. r ∈ S implies r ≤ sup S. S ≤ r implies sup S ≤ r. My god. Somebody revoke my degree.

We HAVE a place for dumping slop preprints already, it's called viXra and it is beautiful

https://github.com/openai/math/tree/main/preprints/The-rational-Hodge-conjecture-for-products-of-K3-surfaces-October-4-2026

I wonder if they tried saying make no mistakes

https://proofsandprompts.com/2026/10/08/100-reactions-to-100-solutions/

Oh damn I'm bleeding through my sweatpants. Well they're fucked now I'm not going to change it

One of the things I dislike most about Jane Street people is their expected value fetishism. If I have to hear "hurr you should miss your flights sometimes to minimize the expected amount of time you spend in the airport" I will scream