#54 The Goal of Science is to Communicate Ideas! - Philip Wadler
Philip Wadler is a well known, celebrated and recognized researcher in the field especially for his unique ability to explain complex ideas in a simple and elegant way. He got his Bachelor in 1977 at Stanford, his Masters in 1979 and his PhD in 1984 both at CMU. In 2023, he was awarded the distinguished honor of being elected a Fellow of the Royal Society, joining the ranks of scientific greats such as Isaac Newton and Charles Darwin.
Wadler describes himself as someone who likes to bring theory into practice, and practice into theory. In this episode, we talk about his prolific research, the story behind Monads and Type Classes, Category Theory and Homotopy Type Theory.
Throughout our conversation, in response to my eagerness to understand the philosophy and method behind his remarkable papers, he repeatedly emphasizes that the whole point of science is clearly communicating ideas so that others can build upon them.
Links
Wadler's Website
Ullman's Advising Students For Success
Grad School Mentorship
Consider contributing to this show through our ko-fi!
-------- Â
1:50:05
--------
1:50:05
#53 RustBelt, Iris, and the Art of Writing - Derek Dreyer
Derek Dreyer is a professor at the Max Planck Institute, in 2024 he was awarded the ACM Fellowship, in 2017 he got the ACM Sigplan Robin Milner Young Researcher Award. And has participated or lead greatly influential work, such as the RustBelt Project and Iris.
In this episode Derek shares his experience going to Grad School at CMU, how even a great research as himself has fallen pray to the impostor syndrome and how to cope with it. Throughout the conversation he makes beautiful parallels between music and academic papers, and how the work of a researcher is similar to that of an artist an many aspects. He also gives us a few tips about how to become a better academic writer. And of course, we also talked about Rust and the history about formally verifying its type system.
Don't forget to check our merch store!
Links
Derek's Website
POPL '25 PLMW Talk - How to Write Papers so that People Can Read Them
-------- Â
2:25:22
--------
2:25:22
#52 Why is Haskell so special - Lennart Augustsson
Lennart Augustsson has spent the last four decades quietly — and sometimes mischievously — shaping the way we think about code.
He co-authored Lazy ML in the early 80s, wrote A Compiler for LML back in 1984, and was behind HBC, the first publicly available Haskell compiler.
If you've used Haskell, worked with hardware described in Bluespec, or played around with weird combinator-based toy languages, there's a decent chance you've crossed paths with his ideas — directly or indirectly.
He's also won the International Obfuscated C Code Contest — not once, but multiple times — reminding us that playfulness and rigor aren't mutually exclusive.
But his work didn't stop in academia or hobby projects. He’s brought functional programming into finance, hardware design, large-scale industry — with stints at Credit Suisse, Facebook, Google, and now Epic Games, where he’s helping design a new functional logic programming language called Verse.
Over the course of this conversation, we’ll talk about lazy evaluation, type theory, programmable dungeons, the compromises of real-world programming, and what it means to still be building languages after 40 years in the game.
Links
Type Theory Forall Merch Store
Ko-Fi
Discord Server
Haskell Interlude
Lennart's Wikipedia Page
Lennart's Webpage
-------- Â
1:30:31
--------
1:30:31
#51 s/Coq/Rocq - Nicolas Tabareau
In this episode we talk with Nicolas Tabareau, the Head of Gallinette, one of the main teams which develop the Rocq theorem Prover at Inria.
The original idea of this interview is to talk about the rebranding from Coq into Rocq, which is very exciting to our community. However, Nicolas has such a prolific research career that I couldn’t miss the opportunity to get him to talk so much more about it.
So in this conversation we talk about his early publications in neuroscience, his views on Category Theory applied to Type Theory, Rocq’s rebranding, and the institution around it, MetaRocq and the conceptual boundaries of certifying a theory inside itself. Of course we wouldn’t miss the opportunity to also discuss how Rocq view the growing influence that Lean is gaining in our community.
Links
Type Theory Forall Store
Type Theory Forall Website
Nicolas Tabareau Website
MetaRocq Github
-------- Â
1:42:05
--------
1:42:05
#50 The Expression Problem, Functional Pearls, Program Calculation - Wouter Swierstra
Wouter Swierstra is a Math Bachelor’s from the University of Utrecht, has done his PhD with Thorsten Altenkirch at the University of Nottingham, did a post-doc at Chalmers, has experience in the industry working on facilitating the design of embedded system using FP and currently is a Professor at the University of Utrecht and co-host of the Haskell Interlude Podcast.
In this episode we talk about his trajectory into formal methods and functional programming. We talk about Datatypes a la Carte, the Expression Problem, Functional Pearls, Program Synthesis vs Program Calculation, and much more!
0:00 – Intro & Welcome
0:02:08 – Announcing the Type Theory Forall Merch Store!
1:12 – Early Influences: From Lenses to Logic
4:40 – Discovering Functional Programming in Utrecht
8:15 – On Monads, Papers, and Learning by Teaching
12:20 – What Makes a Paper ‘Beautiful’?
17:50 – PhD in Nottingham: Theory Meets Community
22:00 – Writing ‘Certified Programming with Dependent Types’
29:10 – Teaching Dependent Types: Challenges and Joys
34:00 – On Agda vs Coq: Philosophies and Use Cases
38:40 – Type-Driven Development in Practice
45:05 – The Power of Elegant Proofs
52:00 – Advice to Aspiring Researchers in Type Theory
1:03:00 – Beating C with Functional Programming
1:20:00 – Formal Verification and Loop Invariants
1:33:28 – Program Calculation vs Program Synthesis
1:39:00 – Formalizing Blockchain
2:01:38 – Final Thoughts
Links
Wouter Website
Haskell Interlude
Advanced FP Summer School
ttforall twitch
ttforall store
Discount code for 10% off: typetheory
Canada - english