Iris van der Giessen is a postdoc at the Institute for Logic, Language and Computation (ILLC) working in mathematical logic. Her main research interests lie in proof theory, a field that studies mathematical proofs as formal objects and that provides a tight connection between logic and computation. Within this discpline she is interested in structural proof theory, cyclic proof theory, constructive proofs of interpolation, proofs-as-programs, and proof-theoretic semantics. 

Iris received a Veni grant from NWO to perform her current project titled Finding Interpolants: Proofs in Action. The project investigates interpolation properties in logic (e.g., Craig interpolation, uniform interpolation, ...) which play important roles in mathematical logic and computer science. The aim of the project is to charactirze criteria under which interpolants exist and compute them using methods in proof theory.  

Previously, she was a research fellow in the UKRI project Structure vs. Invariants in Proofs (StrIP) under supervision of Anupam Das at the University of Birmingham. In 2022, she obtained her PhD at the Utrecht University under supervision of Rosalie Iemhoff and Nick Bezhanishvili. She completed a Master's in Mathematics from the Radboud University Nijmegen in 2018.

Summer schools

Interpolation through the Lens of Proof Theory 
Course at the Logic Summer School @ANU (Australian National University) 2024. The lecture notes can be found here.

Introduction to Proof Theory 
Course at the Midlands Graduate School (MGS) 2024, co-lectured with Abhishek De. Please find the course notes here.

Teaching at UvA

Logic and Computability
Lecturer for third year bachelor course in Artificial Intelligence (2025-2026). 
Course Catalogue

Teaching in other institutes than UvA

Theories of Computation 
Tutor for first year bachelor course in Computer Science, University of Birmingham. (2022-2023)

Logische Complexiteit (Logical Complexity) 
Tutorials and guest lecture for third year bachelor course in Artificial Intelligence, Utrecht University. (2019-2020,2020-2021,2021-2022)

Modale Logica voor KI (Modal Logic for AI) 
Tutorials for second year bachelor course in Artificial Intelligence, Utrecht University. (2020-2021)

Wiskunde voor KI (Mathematics for AI) 
Coordination of first year bachelor course in Artificial Intelligence, Utrecht University. (2018-2019,2019-2020)

Publications

On the Contingency of Logic in Possible World Semantics
Joint work with Joost J. Joosten, Paul Mayaux and Vicent Navarro Arroyo
Logica Universalis, 2025 (doi, arXiv)
Spanish Logic Prize

Mechanised Uniform Interpolation for Modal Logics K, GL, and iSL
Joint work with Hugo Férée, Sam van Gool and Ian Shillito
In proceedings of IJCAR 2024 (doi, arXiv)
Best Paper Award

Uniform Interpolation via Nested Sequents and Hypersequents
Joint work with Raheleh Jalali and Roman Kuznets
Journal of Logic and Computation 2024 (doi, arXiv)
Extended version of WoLLIC 2021 paper

Intuitionistic Gödel-Löb Logic, á la Simpson: Labelled Systems and Birelational Semantics
Joint work with Anupam Das and Sonia Marin
In proceedings of CSL 2024 (doi, arXiv)

A New Calculus for Intuitionistic Strong Löb Logic: Strong Termination and Cut-elimination, Formalised
Joint work with Ian Shillito, Rajeev Goré and Rosalie Iemhoff
In proceedings of TABLEAUX 2023 (doi, arXiv)
Best Paper Award

Extensions of K5: Proof Theory and Uniform Lyndon Interpolation
Joint work with Raheleh Jalali and Roman Kuznets
In proceedings of TABLEAUX 2023 (doi, arXiv)

Admissible Rules for Six Intuitionistic Modal Logics
Annals of Pure and Applied Logic 174(4), 2023 (doi)

Proof Theory for Intuitionistic Strong Löb Logic
Joint work with Rosalie Iemhoff
Accepted for Special Volume of the Workshop Proofs! held in Paris in 2017 (arXiv)

Sequent Calculus for Intuitionistic Gödel-Löb Logic
Joint work with Rosalie Iemhoff
Notre Dame Journal of Formal logic 62(2), 2021 (doi)

Uniform Interpolation via Nested Sequents
Joint work with Raheleh Jalali and Roman Kuznets
In proceedings of WoLLIC 2021 (doi)

Exploring a result by Ghilardi: Projective Formulas vs. the Extension Property
In Logica Yearbook 2020 (url)

Strong Normalization for Truth Table Natural Deduction
Joint work with Herman Geuvers and Tonny Hurkens
Fundamenta Informaticae 170(1-3), 2019 (doi)

Thesis

Uniform Interpolation and Admissible Rules: Proof-theoretic investigations into (intuitionistic) modal logics
Supervisors: Rosalie Iemhoff and Nick Bezhanishvili
Utrecht University 2022 (doi)