Type Theory Forall

In this episode me and Dan Plyukhin get together to have a heartfelt conversation. We start by talking about our experiences with meditation, and how it has helped us to have a more balanced work-life experience. Then the conversation shifts to comment about the current situation of the job market. Both in academia and in industry. We talk about strategies to reach out to professors and our view on the use of AI in general, and of course we talk about our current research interests. Links Consider being a Patreon Check out our merch! Any donations are highly appreciated! Link to Ko-Fi Dan's Website

In this episode of the Type Theory Forall podcast, we are joined by Valeria de Paiva, a Brazilian mathematician and logician whose work has had a lasting influence on category theory, type theory, and the foundations of logic. She is also a co-founder of the Topos Institute, where she continues to explore deep connections between mathematics, logic, computation, and the sciences. Valeria completed her PhD at Cambridge in the mid-1980s. Even today, pursuing an academic career abroad from Brazil is challenging; doing so at that time — and as a woman — required exceptional determination and resilience. Her trajectory alone already makes her an inspiring figure in the field. This episode is one of the most technically focused conversations on category theory we have ever had on TTFA. Coming from a strong mathematics background, Valeria has worked extensively on categorical semantics, logical interpretations, and the interface between logic, computation, and language. As a result, the discussion goes deep into categorical ideas and their role in type theory. Valeria is also the founder of the Women in Logic initiative, which enabled a serious and thoughtful discussion about gender inequality in logic, type theory, and computer science. The conversation is grounded not only in abstract principles, but in decades of concrete work building communities, workshops, and long-lasting support structures for women in the field. Overall, this episode brings together technical depth, personal history, and a broader reflection on what it means to build a healthier and more inclusive research culture in logic and programming languages. 🔗 Links 👩‍🏫 Valeria de Paiva Website Twitter / X Women in Logic Topos Institute 📚 Type Theory Forall TTFA Store Patreon

Andrej Bauer has done his PhD at CMU under Dana Scott, and he stands right on the edge between mathematics and computer science. During our conversation it just feels that he can just go on in depth about any topic remotely related to Type Theory and Programming Languages. Andrej is the person who organized for the The Proof Assistants stack exchange. He has an incredible blog that’s always a great resource to learn Type Theory and Programming Languages Theory. He also has an incredible series of summer school lectures on effect handlers. But more specifically today we talk about Constructivism, Dialectica, Effect Handlers and AI. I’m sure you guys are gonna love it! Links Andrej's Website Andrej's Blog

Raghav Malik, has just defended his PhD on the topic of compilers for privacy-preserving computation, and that's a good chunk of our conversation. He has also spent some years in grad school going down the rabbit hole to actually learn Category Theory in depth and from first principles, so I was deieing to ask him if category theory is really all that to learn the foundations of PL. In other words, does learning category theory really make you a better PL researcher? Then, of course, I wouldn’t finish this episode without asking him how he coped with Mental Health during his PhD Journey. Links Raghav's Website TTFA Patreon TTFA Merch Store TTFA Ko-Fi

Francille Zhuang is an undergrad at Purdue University and has been doing research with Benjamin Delaware and Patrick Lafontaine. In this episode we talk about her early research experiences on Property Based Testing, and we go through all the necessary information for applying for graduate school in Programming Languages in the US. Links Francille's LinkedIn TTFA Mentorship Program TTFA Merch Store TTFA Patreon TTFA Ko-Fi

Mike Sperber is the CEO of Active Group, a company designed for Counseling, Development and Training in functional programming. He is a co-organizer of Bob Konf and FunArch, the Co-founder of the leading german blog on functional programming. Member of the Editorial Board of the JFP. Part of the R6RS, the 6th revised report on the Algorithmic Language Scheme. In our conversation we talk about C, Lisp, Emacs Lisp, Scheme and his involvement with the R6RS. His views on mathematics and formal methods as languages, his views on the use of Functional Programming in the Industry, his thoughts of how Object Oriented Programming is dead. Macros, hygienic macros and much more! We also talk about BobKonf and FunArch as amazing confereces on Functional Programming and their design and archtechture. BobKonf currently has a call for talks open and goes until november 17th. Consider supporting the show! TTFA Patreon One time donations Merch Store Links Mike's Website Bob Konf FunArch Functional Programming Blog TTFA Graduate Mentorship

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!

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

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

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

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

Ryan Brewer is a college dropout who has an incredible blog about PL, Category Theory and Logic. He better define his goal as making Formal Theory more accessible outside the ivory tower of academia, and easier to put into practice where it matters. He has a couple of very interesting main projects, such as the first Cedille 2 Interpreter, Saber VM, and Arctic. In this episode we will talk about all of his projects. His trajectory becoming self-taught in PL, compilers and Formal Methods, and he shares with us the wealth of resources he used to navigate this sea of knowledge. We also have a brief but heated discussion on the ethics of Science. 0:00 – Intro & Podcast Community 3:40 – How Ryan Started Learning Programming Languages 12:40 – Projects, Category Theory & Early Experiences 18:00 – College Life, Dropping Out & Study Strategies 27:00 – Landing a Developer Job Without a Degree 32:00 – Thoughts on JavaScript, TypeScript & WebAssembly 37:00 – Building Arctic: A Compiler for Blogs 41:00 – Introduction to Gleam & Its Unique Features 48:00 – Functional Programming at Work & Community Impact 59:00 – Diving into Haskell and Category Theory 1:08:30 – Ethical Considerations in Software Licensing 1:20:00 – Reflections on Academia & Learning 1:32:30 – Job Interviews & Practical Programming Tools 1:38:00 – Dan on Academia and Podcasting Philosophy 1:54:00 – Final Reflections & Advice for Self-Learners 2:05:00 – Closing Thoughts, Blog, Open Source 2:19:58 – Outro Links Ryan's Website Saber VM Arctic, which is built on top of Lustre Category Theory Wiki

In this episode we continue with our conversation with David MacQueen, he is an Emeritus Professor from the University of Chicago, and has worked at Bell Labs for 20 years. Bell Labs began as the research and development section of the American Telephone and Telegraph company, aka AT&T, which originally hold exclusive hold of the telephone patent. Once that expired in the 1800s they needed to develop new technology to prove that it was still the best company, and hence Bell Labs was born. Over the course of the years this fascinating institution has registered more than 26 thousand patents, among of which we have the transistor, the laser, the solar cell and communication satellites. Over the course of the last 88 years they were awarded a jaw dropping amount of 10 Nobel prizes and 5 Turing awards. In this interview David MacQueen shares with us how was it like to work in such an incredible institution during it’s golden age. He shares insights about the technology, the space, the people, the management style, and much more! Links David's Website David's Github

David MacQueen has worked at Bell Labs for around 20 years during it’s Golden Age. Professor at Chicago University for 23 years. He is one of the designers of SML, one of the fathers of HOPE the programming language that introduced the notion of Algebraic Datatypes. So this interview was very special to me personally where I could get to hear all the stories about the dawn of Functional Programming as we know. And it is my great pleasure to have the honor to share it with you all. Links David's Website David's Github Luca Cardelli and the Early Evolution of ML The History of SML HOPE SML Website SML/NJ Website SML/NJ Github SML Family Website

In this episode Pierre-Marie Pédrot, one of the main Coq/Rocq developers joins us to talk about Krivine, Kleene and Gödel Realizability Models, how it relates to the BHK interpretation and CPS Translations, and how it was all already part of Gödel's work in Dialectica! If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Pierre-Marie's Website Pierre-Marie's PhD Thesis (Very nice read) BHK Interpretation Type Theory Forall website Type Theory Forall discord

In this episode Pierre-Marie Pédrot who is one of the main Coq/Rocq developers joins us to talk about what is Type Theory, what is Martin-Löf Type Theory, what are the properties we should care about in our type theory and why. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Pierre-Marie's Website Type Theory Forall website Type Theory Forall discord

Mario Carneiro is the creator of Mathlib, Lean4Lean and Metamath0. He is currently doing his Postdoc at Chalmers University working on CakeML. In this episode we talk about foundations of theorem provers, type systems properties, semantics and interoperabilities. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Lean4Lean github Metamath Metamath0 Lean Foundations Discussion Large Elimination / Singleton Elimination Type Theory Forall website Type Theory Forall discord

In this episode Eric Bond and Patrick Lafontaine joins us to talk about the life in industry vs the life in academia. Eric is a PhD student at Michigan University under Max New, he works with some pretty cool esoteric cubical agda stuff. Before starting his PhD he has spent some time at the consultancy companies Two Six Technologies and 47 Degrees doing some cool functional programming and formal methods. Before that we were pals doing an internship at Galois, and even before that he finished his masters with Benjamin Delaware at Purdue, Patrick’s current advisor. Patrick has just returned from his internship at AWS in the automated reasoning team. So in this episode we talk about their research, their academic and industry experiences, how’s the industry looking like for opportunities in PL and all that. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall

In this episode we talk with Fabrizio Montesi, a Full Professor at the University of South Denmark. He is one of the creators of the Jolie Programming Language, President of the Microservices Community and Author of the book 'Introduction to Choreographies'. In today’s episode we talk about the formal side of Distributed Sytems, session types, the calculi that model distributed systems, their type systems, their Curry-Howard correspondences, and all the main ideas around these concepts. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Fabrizio's Website Fabrizio's Linkedin Fabrizio's X / Twitter Fabrizio's Mastodon Fabrizio's Youtube Jolie's Website

Satnam Singh has got incredible experience in both academia and industry. He has worked in Google, Facebook, Microsoft, Microsoft Research, Xilinx, etc. He has been a lecturer in Glasgow, Birmingham and University of California for a couple of years. He has worked with many interesting tools such Coq, Haskell, Verilog, Tensorflow. These days he works at Groq, applying FP to design silicon for machine learning. In this episode we talk about the value of specification, the current state of academia, gaming the metrics, functional programming in hardware, bullying, among other things. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Personal Website Satnam's X Groq

In this episode we go into a deep dive into the formal methods side of Voting systems, and for this nobody better than our guest: Joe Kiniry, A Principal Scientist at Galois, Principled CEO and Chief Scientist of Free & Fair, a Galois spin-out focused on high-assurance elections technologies and services. For the past 20 years Joe has worked tirelessly in designing, developing, supporting and auditing all kinds of voting systems for different private parties and government parties. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Broken Ballots Joe Website Galois website SAW

In this episode we continue our conversation with David Christiansen, he wrote the books Functional Programming in Lean and the Little Typer. He has also worked as the Executive Director of the Haskell Foundation, at Galois and did his PhD developing a bunch of cool stuff for Idris. In today’s episode we talk about the story behind writing The Little Typer together with Dan Friedman, and we get more technical by talking about Equality, Bidirectional Type Checking, Quotation and Quasi Quotation. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links: David's Website David's X Lean Zulip Chat Truth of a proposition, evidence of a judgement, validity of a proof

In this episode we talk with David Christiansen, he wrote the books Functional Programming in Lean and the Little Typer. He has also worked as the Executive Director of the Haskell Foundation, at Galois and did his PhD developing a bunch of cool stuff for Idris. David is a super upbeat person and I feel that we could spend hundreds of hours talking about Functional Programming Writing and Dependent Types, and we still wouldn’t run out of topics! If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall

In this episode we talk with Guannan Wei, from Purdue University. Guannan finished his PhD last year under Tiark Rompf, and is currently doing his Post-Doc with Tiark. Guannan has worked on a plethora of different compilers topics, and in this conversation we will talk about Staging, Futamura Projections, Symbolic Execution, Compiler Applications in Smart Contracts and Quantum Programming. Towards the end of the episode we also talk about his application experiences for the position of a Professorship in the US an a few other contries. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Guannan's Website @guannanwei on X

In this episode we celebrate 3 years of existence of this podcast by reflecting on the journey so far, what is my philosophy, how do I approach the interviews, my overall goals for the show, and some of our plans for the future. In order to achieve this, I first take a detour and tell you a little more about my personal history, and my carreer in type theory and programming languages. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall

In this episode we talk with Eduardo Rafael. He is self-thaught programming languages enthusiast, youtuber, twitch streamer, multi-skilled programmer that has worked in different aspects of computer science such as PL, operating systems, blockchain, and many other stuff. In this conversation we talk about his experience as a developer and hacker that didn’t follow the conventional paths of going to school and what are the strategies to navigate the vast ocean of knowledge without guidance of teachers or institutions. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Eduardo's Twitter Eduardo's Twitch Eduardo's Youtube Feynman Algorithm

Andrew Marmaduke is a PhD Candidate from the University of Iowa, he works under Aaron Stump and has been working on revamping the theorem prover Cedille 2. In this episode we tackle fundamental questions about the foundations of the theorem provers, Cedille and Cedille 2. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Andrew's Website AndrasKovacs' Smalltt Failure of Normalization in Impredicative Type Theory with Proof-Irrelevant Propositional Equality Impredicative Encodings of (Higher) Inductive Types

Not satisfied with implementing one of the most popular automated theorem provers, Z3, Leo de Moura also tackles another extremely hard problem in our field and implements a brand new interactive theorem prover from scratch, Lean. In this episode we dive into the mind and philosophy of this man. If you enjoy the show please consider supporting us at our ko-fi: https://ko-fi.com/typetheoryforall Links Leo's Website Lean Z3 The Church of Logic Podcast

In this episode we continue our conversation with Jan de Muijnck-Hughes a Research Associate at Glasgow University. He works using all sorts of fancy type systems mostly targeted for hardware specification, particularly with the aid of the theorem prover Idris. This episode we start by talking a little about Impostor Syndrome in academia and how he has learned to cope with it and then we dive deeper into the technicalities of his research, in particular his philosophy on Type Directed Design of Systems. We talk about Session Types, Graded Types, Quantitative types, etc. Don't forget to join our new discord channel! If you like our show please consider donating any amount at ko-fi. Links Jan's website Jan's twitter Jan's mastodon Writing and Speaking with Style Artifact Eval Andrej Bauer: Formalising Invisible Mathematics Hedy language (Felienne Hermans) Hermans' Inaugural Lecture on making PL human and inclusive Epistemic Injustice Richard Eisenberg interview 'Software Foundations' but in Agda 'System F for Fun & Profit' Reviewing Project Pages https://dsbd-appcontrol.github.io/ https://border-patrol.github.io/ Cool People Rachit Nigam Clement Pit-Claudel Software Idris Language Biblio

In this episode we have a deep conversation with Jan de Muijnck-Hughes, talks about all the cool research he has done with idris, hardware and different kinds of interesting type systems such as session types, quantitative types and graded types. In the second half we discuss all the different kinds of problems that has been going on in PL academia lately and what we can do as a community to address those issues. Also, we have a discord channel now, join us! If you like our show please consider donating any amount at ko-fi. Errata: Jan mentions 'Jeff Foster' when, in fact, he meant Nate Foster This is the SIGCOMM 'Call': https://sigcomm.quest/ Felinne Hermans did her PhD at Eindhoven and not Delft Links Jan's website Jan's twitter Jan's mastodon Writing and Speaking with Style Artifact Eval Andrej Bauer: Formalising Invisible Mathematics Hedy language (Felienne Hermans) Hermans' Inaugural Lecture on making PL human and inclusive Epistemic Injustice Richard Eisenberg interview 'Software Foundations' but in Agda 'System F for Fun & Profit' Reviewing Project Pages https://dsbd-appcontrol.github.io/ https://border-patrol.github.io/ Cool People Rachit Nigam Clement Pit-Claudel Software Idris Language Biblio

In this episode we have over Dan Plyukhin, a PhD Candidate from the University of Illinois Urbana-Champaign. We talk about Dan’s research is in the field of parallelism, more specifically garbage collection in the presence of actors. Then we also talk about Pedro's research on translating GADTs from OCaml to Coq, and the burnout process that lead him to take 10 months off from his PhD to be with his family back in Brazil. Links Dan's Personal Website Twitter: @dplyukhn

Jimmy Koppel, got his PhD at MIT and found the Mirdin Company, where he teaches engineers to write better code! In this interview we talk about how to make better code, how the knowledge of computer science theory and programming languages can help engineers to achieve that, and much more! Links Jimmy's Personal Website Jimmy's Twitter Mirdin's Website Jimmy's Blog Lastest blog post One CFG-Generator to Rule Them All Automatically Deriving Control-Flow Graph Generators from Operational Semantics Thiel Fellowship Newsletters discussed in the show Mirdin's Newsletter Hillel Wayne's Newsletter Eric Normand's Newsletter Jeremy Kun's Newsletter

In this episode we host another company that does formal method in the context of the Everscale Blockchain, and Solidity smart contracts. How and why they use formal methods in this context? Who are their clients? What are the caveats? Links Pruvendo's Website Pruvendo's Linkdin Pruvendo's Twitter

In this episode talk with Gerwin Klein about the formal verification of the microkernel seL4 which was done using Isabelle at NICTA / Data61 in Australia. We also talk a little about his PhD Project veryfing a piece of the Java Virtual Machine. Links Gerwin's Twitter Gerwin's Website ProofCraft's Website

Kevin Buzzard has been very passionate spreading the word among mathematicians to use theorem provers mechanize theorems of modern mathematics. In this conversation we will talk about his vision in teaching undergrads to use the Lean theorem prover, what is the Xena Project, his view of how theorem provers can change the way we do mathematics, and much more! Links Xena's Project Twitter Xena Project's Website Lean's Website

In this episode we partner with Formal Land, a company that works in formally verifying the Tezos codebase! I have worked with them in the past developing new features to their source-to-source compiler CoqOfOcaml. In this episode we talk about their work with Tezos and how their techniques are applicable to other codebases as well! For this we talk with Formal Land founder Guillaume Claret and the proof engineers Daniel Hilst and Pierre Vial. Links Formal Land Website Formal Land Email: [email protected] Formal Land Twitter: @LandFooBar CoqOfOcaml The DAO hack

In this episode we interview Lawrence Paulson, one of the creating fathers of Isabelle. We talk about the development process, how it drew inspirations and ideas from LCF and Boyer Moore. What tools were used, it’s strenghts and weaknesses, and all about the historical context at the time! We also briefly talk about his formalization of the Gödel's Incompletenes theorems in Isabelle Paulson have quite an extensive CV, he is a professor at Cambridge, have published more than 100 papers, is an ACM fellow since 2008, is a member of the royal society since 2017, among many other things! Links Larry's Website Larry's Twitter Larry's Blog

In this episode we talk about Sigplan, the organization behind the most important conferences and proceedings in our field. What is the SIGPLAN? What exactly does it do? How is it organized? How are things published? To answer these and many other questions we talk with Jens Palsberg, a professor at UCLA, who is the past chair of the SIGPLAN. And also Jonathan Aldrich, a professor at the CMU, who is a member of the ACM publication board. Links Jen's Website Jonathan's Website Jonathan's Twitter Sigplan Blog Post on Hybrid Conferences SIGPlAN-M Mentoring Program

In this episode Cody Roux teaches some interesting concepts that people care about in Mathematics and Logic as a way to try to understand what is going on in the universe around us! In particular we will try to explain concepts such as Impredicativity, Excluded Middle, Group Theory, Model Theory, Kripke Models, Realizability, The Markov Principle, Cut Elimination, and other stuff! Links Cody's website Cody's dblp

In this episode Conal Elliott gives a more concrete presentation on what is Denotational Design is and how to use it in practice. It is a continuation of episode #17, in which we had an in-depth philosophical conversation to explain why he believes that Denotational Design is a superior form of reasoning in the realm of computer science. We also continue a discussion raised by Dan Ghica on the last episode on the need for Operational Semantics and the role of elegance in reasoning and design. Along the way we also address the questions sent by the listeners in these last episodes. Links Conal's website Play/work with Conal Conal's twitter: @conal The simple essence of automatic differentiation Compiling to categories Generic parallel functional programming Denotational design with type class morphisms Quotes "A theory appears beautiful or elegant [...] when it’s simple; in other words when it can be expressed very concisely in terms of mathematics that we’ve already learned for some other reasons." - Murray Gell-Mann, Beauty and Elegance in Physics. "In Galileo’s time, professors of philosophy and theology—the subjects were inseparable—produced grand discourses on the nature of reality, the structure of the universe, and the way the world works, all based on sophisticated metaphysical arguments. Meanwhile, Galileo measured how fast balls roll down inclined planes. How mundane! But the learned discourses, while grand, were vague. Galileo’s investigations were clear and precise. The old metaphysics never progressed, while Galileo’s work bore abundant, and at length spectacular, fruit. Galileo too cared about the big questions, but he realized that getting genuine answers requires patience and humility before the facts." - Frank Wilczek, (The Lightness of Being: Mass, Ether, and the Unification of Forces) "We must make here a clear distinction between belief and faith, because, in general practice, belief has come to mean a state of mind which is almost the opposite of faith. Belief, as I use the word here, is the insistence that the truth is what one would ‘lief’ or wish it to be. The believer will open his mind to the truth on the condition that it fits in with his preconceived ideas and wishes. Faith, on the other hand, is an unreserved opening of the mind to the truth, whatever it may turn out to be. Faith has no preconceptions; it is a plunge into the unknown. Belief clings, but faith lets go. In this sense of the word, faith is the essential virtue of science, and likewise of any religion that is not self-deception." - Alan Watts (The Wisdom of Insecurity: A Message for an Age of Anxiety)

In this episode, me and Eric Bond have a great conversation with Dan R. Ghica, a professor at Birmingham University and Director of the Programming Language Research Lab of the Huaweii Research Centre Edinburgh. We talk about his work on both institutions, which includes topics such as Category Theory, String Diagrams, and Game Semantics. We also briefly discuss the current publication process of our field and entertain some thoughts on how to make it better. Finally, we touch on more personal topics such as his views about Elegance, making an insightful counterpoint to Conal’s opinions on Denotational Semantics vs. Operational Semantics. Links Dan's Twitter: @danghica Dan's Website Job advert for Huawei positions Talks and Lectures Dan's talk on Syntactic Trinitarianism (terms, graphs, diagrams) Dan's talk on a similar, more semantics-oriented talk at TERMGRAPH Dan's OPLSS course on (denotational) game semantics Game semantics lectures Papers Paper on string diagrams and their applications to reverse automatic differentiation (long paper, part of it to appear in FSCD 2020) Paper on automatic differentiation and string diagrams Paper on effect handlers Paper on optimisation with constructive reals Paper on digital circuits and string diagrams Paper on functorial boxes for string diagrams A Game semantics paper mentioned during the conversation Decidability via game semantics Landmark paper on undecidability of observational equivalence Other Links Penrose book Book on type-level string diagrams Proof assistant for higher categories The Programming Journal Midlands Graduate School

In today’s episode I invite two friends of mine Patrick Lafontaine and Supun Abeysinghe. We will talk about their experience learning Coq and we guide ourselves in a survey that I gave all the 83 students in the class. The class was thought by my advisor Benjamin Delaware and I was his TA. Patrick researches compilers and have done work in particular with Rust. And Supun works more along the lines of machine learning in the context of systems.

In this episode Cody Roux talks about the Gödel's Incompleteness Theorems. We go through it’s underlying historical context, Hilbert’s Program, how it relates with Turing, Church, Von Neumann, Termination and more. Links Cody's website Cody's dblp The Lady or the Tiger? - Short Story The Lady or the Tiger? - Amazon Logicomix An Introduction to Gödel's Theorems Jeremy Avigad's Lecture Notes

In this episode I had the pleasure to have an in-depth conversation with Conal Elliott about his life, his work, his philosophy and his many opinions about research and the current state of PL Research and how it lead him to come with the concept of Denotational Design. Conal got his PhD at CMU in the 90s under Frank Pfenning working on Higher-Order Unification, after that he has devoted his life on thinking and refining graphic computation and the tools behind it. Links Conal's website Play/work with Conal Conal's twitter: @conal The simple essence of automatic differentiation Compiling to categories Generic parallel functional programming Denotational design with type class morphisms Functional Images Functional Reactive Animation Alphabet Versus the Goddess - Leonard Shlain The information - James Gleick Murray Gell-Mann’s definition of beauty/elegance: "A theory appears beautiful or elegant [...] when it’s simple; in other words when it can be expressed very concisely in terms of mathematics that we’ve already learned for some other reasons." A John Backus quote (from his Turing Award lecture): “Many creative computer scientists have retreated from inventing languages to inventing tools for describing them. Unfortunately, they have been largely content to apply their elegant new tools to studying the warts and moles of existing languages. After examining the appalling type structure of conventional languages, using the elegant tools developed by Dana Scott, it is surprising that so many of us remain passively content with that structure instead of energetically searching for new ones.”

In this episode we interview Jesper Cockx, one of the core developers on Agda. We talk about the philosophy behind Agda, his work on pattern matching, the Uniqueness of Identity of Proofs, UIP for short, and why it is inconsistent with Homotopy Type Theory. Links Jesper's Website Jesper's Twitter: @agdakx Jesper's PhD Thesis Rewrite Theory paper Pattern matching without K paper (Check his website for more) EuroProofNet WITS Talks on Youtube (Workshop on the Implementation of Type Systems) Agda Zulip Agda Mailing List Ataca Github Wadler's book on Agda Stump's book on Agda

In this episode me, Eric and Nitin continues our conversation started in the last episode. This time we move our attention to the cool projects happening in Coq, in particular commenting through the projects mentioned in Andrew Appel’s keynote “Coq’s Vibrant Ecosystem for verification engineering” that took place in CPP’22 which is colocated with POPL and towards the end we also talk about agda, idris and Kind. Links Nitin Twitter @NitinJohnRaj2 Eric Twitter @EricBond10 Appel's CPP Talk Proof Assistants Stack Exchange Coq Community Leo de Moura Interview

In this episode I gather with two good friends Eric and Nitin to randomly talk random subjects that pops up. Among them we talked about POPL, Scala, Isabelle, Parametricity, Dependent Object Types (DOT, for short) and more! Links Nitin Twitter @NitinJohnRaj2 Eric Twitter @EricBond10 Collection of links on logical relations Theorems for Free Reynolds Paper Practical Foundations for Programming Languages

This episode is about the journey of a programmer that converted himself into a Haskell developer after working with C/C++ for more than 10years. Here are a few questions that you'll find the answer to in this episode: What does he find so compelling about Haskell? Why did it make him dive deeper into the Theoretical Computer Science? Why did it make him learn Coq and Category Theory? How does Coq compare with ACL2? How do both Coq and ACL2 compares to TLA+? Did learning Coq make John a better programmer? Links John's Email: [email protected] John's Twitter: @jwiegley

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