
Type Theory Forall
An accessible podcast about Type Theory, Programming Languages Research and related
topics.
Latest episodes

Nov 10, 2021 • 1h 6min
#12 Tenure, Sexism and ADHD - Talia Ringer
Talia Ringer is an Assistant Professor at University of Illinois
Urbana-Champaign. She did her PhD at University of Washington with her thesis
on Proof Repair.
She’s very active on twitter @taliaringer. And in this episode we will talk
about her transition from PhD to Professor, her work on diversity, her ADHD and
how it has affected her career so far, and we also touch on the delicate topic
of sexism in academia.
Links
Talia's Twitter
Sigplan Mentoring
TIL: a type-directed, optimizing compiler for ML
Neuro Divergent in CS
Neuro Divergent in CS - Slack
Overblur

Oct 4, 2021 • 1h 7min
#11 FP, Monads, GHC, and beyond - Alejandro Serrano
In this episode we have talk with Alejandro Serrano Mena, he
works on 47 degrees and is a published author of two books about Haskell: The
Book of Monads and Practical Haskell.
We talk about many interesting features behind functional
programming such as adts, pattern matching, impredicativity, monads, effects,
hacking the ghc and how all this comes together to grab industry attention to
adopt functional programming features over the past decade.
Links
Our new twitter @ttforall
Alejandro's twitter
Book of Monads
Practical Haskell
The Haskell Interlude
Tweag's youtube channel on the GHC

Jul 15, 2021 • 1h 17min
#10 Classical Logic vs Intuitionistic Logic - Thorsten Altenkirch and Anupam Das
In this episode we host a discussion between Anupam Das and Thorsten
Altenkirch on the role of constructivism in mathematics, logic and computer
science.
Anupam is a lecturer in the University of Birmingham in the UK, and Thorsten
Altenkirch is a CS Professor at the University of Nottingham.
We discuss why constructive content in proofs matters, the law of excluded
middle, the axiom of choice, category theory, and much more!
Links
Thorsten's website
Anupam's website
Thorsten's Book on Python
The Proof Theory Blog
High School Algebra
Stanford Encyclopedia of Philosophy

May 28, 2021 • 57min
#9 Logic and Proof Theory - Anupam Das

May 11, 2021 • 1h 6min
#8 Cedille - Chris Jenkins
In this episode I have a nice conversation with Chris Jenkins to talk about
the Cedille theorem prover, based on a very concise type theory called CDLE.
The main selling point of Cedille is that the theory is so small that the
typing rules fit one page. And yet it is strong enough to do relevant theorem
proving. This is probably the most technical episode so far.
Links
Leroy Jenkins
Cedille Cast
The Iowa Type Theory Commute
Cedille Page
Github Page

Apr 16, 2021 • 1h 21min
#7 Hacking Isabelle's Internals - Dan Matichuk
In this episode we dive into Isabelle, the interactive theorem prover based on Higher Order Logic directly from someone who spent quite some time hacking on its internals.
Me and Daniel also talk about Mizar, Isar, the seL4, and how it is formalized.
Torwards the end of the episode we also talk a little about his current work on the binary analysis of Aarch32 Arm Archtecture at Galois.

Mar 29, 2021 • 39min
#6 All The Dumb Questions on Gradual Types - Zeina Migeed
In this episode we interview Zeina Migeed, a PhD Student at University of
California Los Angeles, advised by Prof. Jens Palsberg
She Researches Gradual Types and had a paper published at POPL'20 named "What is
Decidable about Gradual Types". here is a link to it
As the name of the episode suggests, I'll be asking her all the dumb questions
related to not only gradual types, but also intersection types and recursive
types as well!

Feb 27, 2021 • 1h 12min
#5 The History of Coq'Art - Yves Bertot
In this episode we interview Yves Bertot and we talk about the history behind his contribution with Pierre Castéran on writing Coq’Art. What is Yves’ role in the Coq Team, how the team works and what are the sort of contributions they accept.
Links:
Yves email: yves.bertot@inria.fr
Affichage et manipulation interactive de formules mathématiques dans les documents structurés - Check figure 15 for an example on how Yves’ tools would build trees internally
A video showing his tool in practice, doing proofs with mouse clicks
A Genereic Approach to Building User Interfaces for Theorem Provers

Feb 15, 2021 • 1h 14min
#4 Theorem Provers, Functional Programming and Companies - Eric Bond
Eric Bond works at 47 degrees, a consulting firm specializing in Functional Programming. He shares insights into the rise of Lean in formal verification and the challenges of Haskell, contrasting it with Isabelle and Coq. The conversation highlights innovations in functional programming and type theory, especially in the context of the pandemic, promoting best practices in consulting. Eric also discusses the growing relevance of formal verification in the cryptocurrency space, alongside the enriching contributions of programming communities.

Feb 1, 2021 • 1h 8min
#3 ML for PL and Mental Health - Dan Zheng
In this episode we host Dan Zheng, an alumni of Purdue University that now works at Google at real cool projects that relates ML and PL.
We chat about how was his transition from undergrad to such a huge company like Google. We talk about cool languages such as Lantern, LLVM, LMS, Julia, Rust, Racket, Scala. How does ML and PL can be used to enhance each other. And towards the end we shift our attention to mental health, both in the academia and in the industry.
You can find Dan at twitter @dancherp