Ken Sakayori (酒寄　健)

I’m a 助教 (jokyo, assistant professor) of the Department of Computer Science,
Graduate School of Information Science and Technology,
The University of Tokyo. I’m a member of the Kobayashi Lab.

(I also work as a part-time lecturer at Waseda University.)

Before that I was

• a happy postdoc at the Department of Computer Science and Engineering, University of Bologna, and also a member of the INRIA FoCUS Research Team
• a fresh postdoc and a PhD student at the Kobayashi Lab under the supervision of Naoki Kobayashi.

Research Interests

I study semantics of (concurrent) programs. More specifically, I like to investigate programs at the granuality in which both operational (e.g. LTS) and denotational (e.g. categorical) semantic insights can be used. Broadly speaking, my interest lies in the field of programming language semantics, logics (in computer science) and programming verification.

Publications

• Hiroyuki Katsura, Naoki Kobayashi, Ken Sakayori, and Ryosuke Sato
  Automated Catamorphism Synthesis for Solving Constrained Horn Clauses over Algebraic Data Types
  To appear in Proc. SAS 2025, Preprint at arXiv

• Ken Sakayori and Davide Sangiorgi
  Extensional and Non-extensional Functions as Processes
  LMCS, 2025
  (A journal version of our LICS 2023 paper invited to a special issue.)

• Risa Yamada, Naoki Kobayashi, Ken Sakayori, and Ryosuke Sato
  On the Relationship between Dijkstra Monads and Higher-Order Fixpoint Logic
  Proc. ESOP 2025
  Distinguished Paper Award
  [Publisher version: © Springer]

• Hiroyuki Katsura, Naoki Kobayashi, Ken Sakayori, and Ryosuke Sato
  Mode-based Reduction from Validity Checking of Fixpoint Logic Formulas to Test-Friendly Reachability Problem
  Proc. APLAS 2024
  [Publisher version: © Springer]

• Izumi Tanaka, Ken Sakayori, and Naoki Kobayashi
  Ownership Types for Verification of Programs with Pointer Arithmetic
  Proc. PEPM 2024
  [Publisher version: © ACM, Preprint at arXiv, Errata]

• Takashi Nakayama, Yusuke Matsushita, Ken Sakayori, Ryosuke Sato and Naoki Kobayashi
  Borrowable Fractional Ownership Types for Verification
  Proc. VMCAI 2024
  [Publisher version: © Springer, Preprint at arXiv]

• Ken Sakayori and Davide Sangiorgi
  Extensional and Non-extensional Functions as Processes
  Proc. LICS 2023
  Distinguished Paper Award
  [Publisher version: © IEEE, preprint at HAL]

• Tsubasa Shoshi, Takuma Ishikawa, Naoki Kobayashi, Ken Sakayori, Ryosuke Sato, Takeshi Tsukada
  Termination Analysis for the π-Calculus by Reduction to Sequential Program Termination
  Proc. APLAS 2021
  [Publisher version: © Springer-Verlag, preprint at arXiv]

• Takumi Shimoda, Naoki Kobayashi, Ken Sakayori, Ryosuke Sato
  Symbolic Automatic Relations and Their Applications to SMT and CHC Solving
  Proc. SAS 2021
  [Publisher version: © Springer-Verlag, preprint at arXiv]

• Ken Sakayori and Takeshi Tsukada
  Output Without Delay: A π-Calculus Compatible with Categorical Semantics
  Proc. FSCD 2021
  [doi:10.4230/LIPIcs.FSCD.2021.32]

• Ken Sakayori and Takeshi Tsukada
  A Categorical Model of an i/o-typed π-calculus
  Proc. ESOP 2019
  [Publisher version (gold open access): © Springer-Verlag, Long version: pdf]

• Ken Sakayori and Takeshi Tsukada
  A Truly Concurrent Game Model of the Asynchronous π-calculus
  Proc. FoSSaCS 2017
  [Publisher version: © Springer-Verlag, Author version: pdf]

Education

• PhD in Information Science & Technology, The University of Tokyo, March 2021
• Master of Information Science & Technology, The University of Tokyo, March 2018
• BSc, The University of Tokyo, March 2016

Grants

• Grant-in-Aid for JSPS Fellows (DC2), Grant Number: 20J13473, Japan Society for the Promotion of Science, April 2020 - March 2021.

How to reach me

• Email: sakayori [at] kb.is.s.u-tokyo.ac.jp
• Address:
  Room 503, Rigakubu 7-gokan,
  7-3-1 Hongo, Bunkyo-ku,
  Tokyo 113-0033,
  Japan
  • Google Maps
  • This page explains how to reach the campus from stations (but it may not be that informative).

Blog

Blog some in English and the others in Japanese.