Portland PLV Seminars

Our seminar series featuring talks on programming languages, verification, and related topics.

Spring 2026

Organizers: Yiming Lin, Julay Leatherman-Brooks

All Talks

Date Title Speaker
A Taxonomy of Hoare-Like Logics Yao Li
Exploring comonads in Haskell Katie Casamento

A Taxonomy of Hoare-Like Logics

Speaker: Yao Li

Yao Li (He/Him) is an assistant professor of computer science at Portland State University. His main research area is in functional programming, interactive theorem proving, and program verification. His current research focuses on using interactive theorem provers to verify existing programs written without verification in mind. He obtained his Ph.D. from the University of Pennsylvania in 2022, under the supervision of Stephanie Weirich.

Abstract

In this talk, I will present a paper I recently read and really liked. The paper is "A Taxonomy of Hoare-Like Logics: Towards a Holistic View using Predicate Transformers and Kleene Algebras with Top and Tests" (https://doi.org/10.1145/3704896). I have always been interested in incorrectness logic, but at the same time, I find it counterintuitive in a few ways; and it puzzles me whether incorrectness is indeed a dual of Hoare logic. This paper presents a very simple and clean framework for considering all these---in fact, it goes further by identifying 8 different kinds of predicate transformers and 16 different Hoare-like logics built upon them. I will discuss this framework in my talk.

Exploring comonads in Haskell

Speaker: Katie Casamento

I'm a PhD student at PSU currently working on automatically deriving decision procedures from dependent datatype definitions in Agda. In my recent free time I've been truckin' and taping Arduinos to sim racing hardware.

Abstract

In this informal guided discussion we'll explore the Comonad typeclass in Haskell as an idiom for structuring programs. Although it's rarely the most immediately practical way to solve a problem, a comonadic presentation highlights the structure of some problems in a unique way, revealing structural similarities between a variety of concepts including cellular automata and coinductive streams. If time permits we'll also explore free comonads and their relationship to free monads: in particular, over a given functor which encodes the syntax of a language, the free comonad is a type of programs and the free monad is a type of interpreters which consume those programs.

Past Terms

Thank You to Our Speakers

We would like to express our gratitude to all the speakers who have shared their research and insights with us:

Alain Kägi, Anastasiya Kravchuk-Kirilyuk, Andrew Black, Andrew Tolmach, Anton Lorenzen, Artem Pelenitsyn, Audrey Seo, Bart Massey, Benjamin C. A. Morrison, Brent Yorgey, Caroline Lemieux, Cassia Torczon, Cheng Zhang, Chris Martens, Daniel Sainati, Earl Wu, Flavio Ascari, Gan Shen, Grant VanDomelen, Greg Anderson, Guido Martinez, Hannah Leung, Ian Kariniemi, J. Garrett Morris, Jacob Prinz, Jialu Bao, John Wiegley, Joomy Korkut, Josh Cohen, Karuna Grewal, Katherine Philip, Katie Casamento, Konstantinos Kallas, Kristopher Micinski, Laura Israel, Li-yao Xia, Lindsey Kuper, Mark P. Jones, Markus de Medeiros, Matthew C. Davis, Michael Arntzenius, Nicholas Coltharp, Patrick Redmond, Samuel Gruetter, Saul Shanabrook, Sean Noble Anderson, Shiwei Weng, Stefan Muller, Steven Libby, Tahina Ramananandro, Tim Nelson, Tobias Reinhard, Tzu-Han Hsu, William Mansky, Yannick Zakowski, Yao Li, Yawen Guan, Zeeshan Lakhani, Zhe Zhou