Then we reopen only for the holidays

If you’ve been thinking about getting something — now’s the time.

Appreciate all the support ❤️
2/2

Dropping 2 new items today in tribute to Tony Hoare:

• C.A.R T-Shirt
• Hoare Triple Hat

A small way to celebrate someone who shaped how we think about programming and correctness.
https://twp.ai/9OVSQV

The store will now only open once a month

⏳ This drop closes May 19
1/2

New TTFA episode

I sat down with Farhad Mehta, one of the main organizers of Zurihac, the largest Haskell event in the world.
We talk about:
• the story behind Zurihac
• what it takes to run it
• Farhad’s path across academia and industry

Zurihac 2026: June 6–8 in Zurich

The store will now only open once a month

⏳ This drop closes May 19

Then we reopen only for the holidays

If you’ve been thinking about getting something — now’s the time.

Appreciate all the support ❤️
2/2

Dropping 2 new items today in tribute to Tony Hoare:

• C.A.R T-Shirt
• Hoare Triple Hat

A small way to celebrate someone who shaped how we think about programming and correctness.
https://twp.ai/9OVKq1

1/2

three mugs, depicting the logos of Agda, OCaml, and Hazel, sitting on office desk

Ordered Agda and OCaml mugs from the @ttforall.bsky.social merch store and Pedro threw in a little bonus! 💚

Happy you liked Cyrus! 😁

men are from Type, women are from Prop

www.patreon.com Patreon

You can get access to the video through the System F tier for $5 using the discount code DFC5C.

https://twp.ai/9PcpYA
4/4

I confess that this is not a super well polished video, but if you like foundational papers discussion, I think you'll enjoy this.

To share this with a slightly broader audience, I’m offering 50% off the first month on Patreon.
3/4

The first episode is out now, and it’s on Frege, centered around his essay “The Thought: A Logical Inquiry.” I think it's a fascinating entry point into how these foundational ideas started to take shape.
2/4

Hey everyone! I’ve just started a short series for Patreons where I study and discuss the story of the logicians that make up the intuitionistic lineage. I'm trying to connect the people, ideas, and historical context in a more linear narrative.
1/4

www.youtube.com #60 - Conversations on Life, AI, and the PL Job Market - Pedro and Dan

New TTFA episode 🎙️

What does it mean to build a research career today?

With Dan Plyukhin we talk about:
• meditation & staying sane
• the reality of the job market
• reaching out to professors
• AI (hype vs reality)
• research paths

“The thought, in itself immaterial, clothes itself in the material garment of a sentence and thereby becomes comprehensible to us” — Frege 1956

tristan.st Tristan Stérin

Tristan Stérin used LLMs to hunt for bugs and inconsistencies in Rocq and Lean.

This is actually pretty neat and kind of wild.

Few researchers have shaped the intellectual foundations of our field so deeply. Thank you, Tony Hoare. May you rest in peace.
7/7

Hoare also introduced null references in ALGOL W, which he later called his “billion-dollar mistake,” a candid reflection that pushed language designers toward safer type systems.

For these and many other contributions he received the ACM Turing Award in 1980.
6/7

He also created Communicating Sequential Processes (CSP), a foundational model for concurrency and message-passing systems that influenced languages and systems for decades.
5/7

In 1969 he introduced Hoare Logic in An Axiomatic Basis for Computer Programming, giving us the famous Hoare triple {P} C {Q} and launching the field of formal reasoning about programs.
4/7

His first idea was insertion sort, but this line of thinking led him to invent Quicksort — still one of the most widely used sorting algorithms in the world.
3/7

In 1960, while a visiting student at Moscow State University working on a machine translation project, Hoare needed a way to sort the words of Russian sentences before looking them up in a Russian–English dictionary.
2/7

Today we honor the life and work of Sir Tony Hoare (1934–2026), one of the giants of computer science. His work shaped algorithms, programming languages, concurrency, and formal verification.
1/7

Some people drink coffee.
Others drink coffee and reason about it formally ☕

FP & proof assistant mugs →
https://twp.ai/9Pb5eO

Some people drink coffee.
Others drink coffee and reason about it formally ☕

FP & proof assistant mugs →
https://twp.ai/9PatXs

Some people drink coffee.
Others drink coffee and reason about it formally ☕

FP & proof assistant mugs →
https://twp.ai/9Pay3E

Some people drink coffee.
Others drink coffee and reason about it formally ☕

FP & proof assistant mugs →
https://twp.ai/9Payr1

For students and engineers working in PL, compilers, or formal verification, understanding these three perspectives is essential. They are not competing views. They are complementary lenses on what programs are and what it means for them to be correct.
8/8

This tradition gave us foundational ideas such as invariants and Hoare logic, emphasizing reasoning as central to programming.

Operational semantics models execution.
Denotational semantics models mathematical meaning.
Axiomatic semantics models provability.
7/8