I am happy to announce that my paper joint with Niels van der Weide, Benedikt Ahrens & Paige Randall North has been published at Computer Science Logic 2025.
We show how univalent mathematics can be used to study intricate (higher) categories. Concretely, we demonstrate that in univalent math we can introduce more precise definitions that are able to incorporate the equivalences we actually care about. Moreover, we apply this approach and study various notions of double categories. Here is a link:
https://doi.org/10.4230/LIPIcs.CSL.2025.45
If you don't have the time or energy to read the paper, you can also check out this talk, where I try to explain the main ideas to mathematicians:
https://www.youtube.com/watch?v=mAjEo8tfsQE
Finally, we also formalized our results in Coq UniMath:
https://github.com/UniMath/UniMath/tree/master/UniMath/Bicategories/DoubleCategories
The POPL paper "Relaxed Memory Concurrency Re-executed" by Evgenii Moiseenko, Matteo Meluzzi, Innokentii Meleshchenko, Ivan Kabashnyi, Anton Podkopaev, and our own Soham Chakraborty was selected for a distinguished paper award. Congratulations to all the authors!
The pre-print for the #ICPC paper “Pinpointing the Learning Obstacles of an Interactive Theorem Prover” by @sarantja @azaidman and yt is now available at https://sarajuhosova.com/assets/files/2025-icpc.pdf
I very much hope this will inspire more research on the usability and accessibility of the languages we build going forward!
Abstract:
Interactive theorem provers (ITPs) are programming languages which allow users to reason about and verify their programs. Although they promise strong correctness guarantees and expressive type annotations which can act as code summaries, they tend to have a steep learning curve and poor usability. Unfortunately, there is only a vague understanding of the underlying causes for these problems within the research community. To pinpoint the exact usability bottlenecks of ITPs, we conducted an online survey among 41 computer science bachelor students, asking them to reflect on the experience of learning to use the Agda ITP and to list the obstacles they faced during the process. Qualitative analysis of the responses revealed confusion among the participants about the role of ITPs within software development processes as well as design choices and tool deficiencies which do not provide an adequate level of support to ITP users. To make ITPs more accessible to new users, we recommend that ITP designers look beyond the language itself and also consider its wider contexts of tooling, developer environments, and larger software development processes.
#Agda #TheoremProving #DependentTypes #Usability #Accessibility #ICPC25
PhD thesis by Hendrik van Antwerpen: "Declarative Name Binding for Type System Specifications"
"This dissertation proposes a novel meta-language, Statix, for the specification of static semantics. Statix supports the direct modeling of surface language name binding features, stays close to a familiar inference-style of specification, and allows automatically deriving implementations for compilers and editor services."
Watch tomorrow at 17h: https://nmclive.tudelft.nl/mediasite/Showcase/public/Presentation/e5b66c56929044a792325e3eec3f04a31d
Pdf: https://repository.tudelft.nl/record/uuid:4bf44aa1-779c-4a96-8c55-5e1b54e16119
I’m very glad to announce that our NWO-XL proposal “Cyclic Structures in Programs and Proofs: New Harmonies of Theory and Praxis” together with Jorge Perez @PerezJorgeA (RUG), Henning Basold (Leiden U), Robbert Krebbers (Radboud U), Georgiana Caltais (U Twente), Helle Hvid Hansen (RUG), and y.t. has been granted!
Here’s the blurb:
From our phones and buildings to power and communication networks, software is the backbone of our digital society. Ensuring that software systems are reliable and resilient is crucial but challenging. A key aspect of verifying software is analysing cyclic structures in their behavior. However, the theoretical understanding of many important cyclic structures is still underdeveloped, creating a bottleneck for verification: many critical software systems essential to society cannot be verified. This consortium will significantly advance the theory of cyclic structures, providing a robust foundation for the future-proof construction of software systems that are reliable and resilient.
The full list of granted projects is available at https://www.nwo.nl/en/news/64-million-euros-for-groundbreaking-fundamental-research-projects
Master thesis by Arnoud van der Leer: Universal Algebra, Univalent Foundations and the Untyped λ-Calculus
"This thesis studies and expands upon Martin Hyland’s paper ‘Classical lambda calculus in modern dress’. [...] The thesis translates Hyland’s paper from set theory with classical logic to univalent foundations, and showcases where subtleties arise in such a translation."
https://repository.tudelft.nl/record/uuid:e6582866-9c0d-4a13-8eda-42c25e0deba4
Master thesis by Jakob Nauke: Compiling Dependent Type Preconditions to Runtime Checks With Agda2Hs
"As an extension to Agda2Hs, we
have implemented a solution to automatically insert runtime checks for the preconditions and only make those definitions accessible in the output that are also checkable."
https://repository.tudelft.nl/record/uuid:0a13ca4a-9d3c-416e-bb88-affc3f14ee52
Excited to share that I'm joining the ACP group at the University of Southern Denmark! Looking forward to new challenges and collaborations ahead.
I'm also grateful for the fantastic experience and connections I leave with from @DelftPL. Looking forward to staying in touch and keep building together!
Next week, Jasper Denkers is defending his PhD dissertation titled "Domain-Specific Languages for Digital Printing Systems" in the Aula of TU Delft.
Spotted in the Haskell Weekly newsletter: heftia-effects, a library for higher-order effects based on the work by @casperbp and @casvdrest
Paper by Jaro Reinders at Haskell 2024: Higher Order Patterns for Rewrite Rules
"We introduce higher order patterns as a simple extension of GHC’s rewrite rules. [...] Our stream fusion framework with higher order patterns shows an average speedup of 7% compared to our stream fusion framework without it."
Extended abstract by Sára Juhošová at TyDe '24: How Novices Perceive Interactive Theorem Provers
"we conducted an online survey among bachelor students, asking them to list the obstacles they encountered while learning Agda. [...]These observations point to one prominent point of improvement: providing a more accessible and sturdy infrastructure for ITP programmers."
Paper by Ivan Todorov and Casper Bach Poulsen at TyDe '24: Modal μ-Calculus for Free in Agda
"Using dependently-typed programming in Agda, we develop an embedding of the modal μ-calculus for defining and verifying functional properties of possibly-non-terminating effectful programs which we represent in Agda using the coinductive free monad."
Master thesis by Olek Wolska:
Towards Modular Language Semantics of WebDSL: A Case Study of Using Algebraic Effects in Haskell for Language Specification
"We adapt the algebraic effects and handlers approach [...] to create a modular denotational semantics model of WebDSL [...] that allows us to distinguish between effects raised by different components of the language."
https://repository.tudelft.nl/record/uuid:47aba90c-b45d-477b-90c0-462e111efdb1
Master thesis by Niyousha Najmaei: The Internal Language of Comprehension Categories
"In this thesis, we first study how MLTT is interpreted in full split comprehension categories through concrete examples. Next, we investigate type theories that can be interpreted in comprehension categories which are not necessarily full and split."
https://repository.tudelft.nl/record/uuid:39e79d29-122c-4b54-827f-fd9908495e17
Master thesis by Alex Haršáni: Embedding Statix in Agda
"Using Statix, we can write a specification using constraints over scope graphs and terms. [...] we introduce a library called statix-in-agda. This library, written using the proof assistant Agda, includes the formalisation of scope graphs and embedding of Statix's constraints."
https://repository.tudelft.nl/record/uuid:8dfeb8f9-4bb3-4f91-8692-b9c9fbb4dadc
Master thesis by Luka Janjić:
Program synthesis with dependent types
"We implement a prototype of a search algorithm driven by unsolved constraints typically generated during dependent type checking. We encode a range of synthesis problems from literature in our system, showcasing how it can be used for expressing the specification and synthesizing programs that manipulate data."
https://repository.tudelft.nl/record/uuid:1cdf7a62-d667-4376-a09b-e46c8bff508c