Simon Oddershede Gregersen

I am a postdoctoral fellow in the Computer Science Department at the Courant Institute of New York University, working with Joseph Tassarotti. I obtained my PhD from Aarhus University in 2023 where I was advised by Amin Timany and Lars Birkedal.

I study programming languages and program verification. My research focuses on techniques to develop formally verified software systems that come with machine-checked mathematical proofs. I am particularly interested in security properties, distributed systems, and randomized programs.

My work is currently supported by an Internationalization Fellowship from the Carlsberg Foundation (CF23-0791).

Contact

E-mail: s.gregersen@nyu.edu
CV (April 2025)

Preprints

Modular Reasoning about Error Bounds for Concurrent Probabilistic Programs
Kwing Hei Li, Alejandro Aguirre, Simon Oddershede Gregersen, Philipp G. Haselwarter, Joseph Tassarotti, Lars Birkedal
arXiv

Publications

Logical Relations for Formally Verified Authenticated Data Structures
Simon Oddershede Gregersen, Chaitanya Agarwal, Joseph Tassarotti
To appear in CCS 2025: ACM SIGSAC Conference on Computer and Communications Security
arXiv

Approximate Relational Reasoning for Higher-Order Probabilistic Programs
Philipp G. Haselwarter, Kwing Hei Li, Alejandro Aguirre, Simon Oddershede Gregersen, Joseph Tassarotti, Lars Birkedal
In POPL 2025: ACM SIGPLAN Symposium on Principles of Programming Languages
PDF DOI arXiv Artifact Coq development

Tachis: Higher-Order Separation Logic with Credits for Expected Costs
Phillipp G. Haselwarter, Kwing Hei Li, Markus de Medeiros, Simon Oddershede Gregersen, Alejandro Aguirre, Joseph Tassarotti, Lars Birkedal
In OOPSLA 2024: ACM SIGPLAN Conference on Object-Oriented Programming, Systems, Languages, and Applications
PDF DOI arXiv Artifact Coq development

Almost-Sure Termination by Guarded Refinement
Simon Oddershede Gregersen, Alejandro Aguirre, Phillipp G. Haselwarter, Joseph Tassarotti, Lars Birkedal
In ICFP 2024: ACM SIGPLAN International Conference on Functional Programming
PDF DOI arXiv Artifact Coq development Slides Talk

Error Credits: Resourceful Reasoning about Error Bounds for Higher-Order Probabilistic Programs
Alejandro Aguirre, Phillipp G. Haselwarter, Markus de Medeiros, Kwing Hei Li, Simon Oddershede Gregersen, Joseph Tassarotti, Lars Birkedal
In ICFP 2024: ACM SIGPLAN International Conference on Functional Programming
Recipient of the ICFP 2024 Distinguished Paper Award
PDF DOI arXiv Artifact Coq development Talk

Asynchronous Probabilistic Couplings in Higher-Order Separation Logic
Simon Oddershede Gregersen, Alejandro Aguirre, Phillipp G. Haselwarter, Joseph Tassarotti, Lars Birkedal
In POPL 2024: ACM SIGPLAN Symposium on Principles of Programming Languages
PDF DOI arXiv Artifact Coq development Slides Talk

Trillium: Higher-Order Concurrent and Distributed Separation Logic for Intensional Refinement
Amin Timany, Simon Oddershede Gregersen, Léo Stefanesco, Jonas K. Hinrichsen, Léon Gondelman, Abel Nieto, Lars Birkedal
In POPL 2024: ACM SIGPLAN Symposium on Principles of Programming Languages
PDF DOI arXiv Coq development

Mechanized Logical Relations for Termination-Insensitive Noninterference
Simon Oddershede Gregersen, Johan Bay, Amin Timany, Lars Birkedal
In POPL 2021: ACM SIGPLAN Symposium on Principles of Programming Languages
PDF DOI Technical appendix Coq development Slides

Distributed Causal Memory: Modular Specification and Verification in Higher-Order Distributed Separation Logic
Léon Gondelman, Simon Oddershede Gregersen, Abel Nieto, Amin Timany, Lars Birkedal
In POPL 2021: ACM SIGPLAN Symposium on Principles of Programming Languages
PDF DOI Technical appendix Coq development

Aneris: A Mechanised Logic for Modular Reasoning about Distributed Systems
Morten Krogh-Jespersen, Amin Timany, Marit E. Ohlenbusch, Simon Oddershede Gregersen, Lars Birkedal
In ESOP 2020: European Symposium on Programming
PDF DOI Technical appendix Coq development Slides Talk

A Dependently Typed Library for Static Information-Flow Control in Idris
Simon Oddershede Gregersen, Søren E. Thomsen, Aslan Askarov
In POST 2019: Principles of Security and Trust
PDF DOI Extended version Idris development

Dissertation

Higher-Order Separation Logic for Distributed Systems and Security
Simon Oddershede Gregersen
PhD dissertation, Aarhus University, March 2023
PDF Slides

Selected talks

Logical Relations for Formally Verified Authenticated Data Structures
New Jersey Programming Languages and Systems Seminar, 9 May, 2025
Slides

Logical Relations for Formally Verified Authenticated Data Structures
Invited talk at the VU Amsterdam PLSec reading group, 16 April, 2025
Slides

Trillium: Intensional Refinement in Higher-Order Separation Logic
Contributed talk at New England Systems Verification Day, 26 April 2024
Slides

Asynchronous Probabilistic Couplings in Higher-Order Separation Logic
Invited seminar at the Bristol Programming Languages Research group seminar, 19 July 2023
Slides

Asynchronous Probabilistic Couplings in Higher-Order Separation Logic
Contributed talk at VeriProP, 17 July 2023
Slides

Trillium: History-Sensitive Refinement in Separation Logic
Contributed talk at The Iris Workshop, 3 May 2022
Slides

Mechanized Logical Relations for Termination-Insensitive Noninterference
Invited seminar at the Chalmers ProgLog/Security seminar, 4 November 2020
Slides