Jon Sterling

9225 Gates Hillman Center
School of Computer Science
Carnegie Mellon University
5000 Forbes Ave
Pittsburgh, PA 15213

ORCID iD icon

I am a doctoral student of Robert Harper at Carnegie Mellon University studying type theory, programming languages and semantics. Previously I received a B.A. in Linguistics from U.C. Berkeley. My other interests include category theory, topos theory, formalization of mathematics, Assyriology, and ancient languages and literature. Check out my new research blog! Access my curriculum vitae


I study the syntax and semantics of type theory and programming languages through the lens of categorical algebra and topos theory, with an aim toward building better interactive proof assistants. I am interested in the design and metatheory of program module calculi as in ML family languages.

My colleagues and I have developed the redtt and cooltt proof assistants for Cartesian cubical type theory.

Recent News

Aug. 2020 thesis proposal presented and accepted
Jul. 2019 received ICFP '19 Distinguished Paper Award
Jun. 2019 received FSCD '19 Best Paper Award for Junior Researchers

Recent Drafts

Jan. 2021
Preprint Normalization for Cubical Type Theory
J. Sterling, C. Angiuli.
Dec. 2020
Preprint Syntactic categories for dependent type theory: sketching and adequacy
D. Gratzer, J. Sterling.
Jul. 2020
Preprint Logical Relations as Types: Proof-Relevant Parametricity for Program Modules
J. Sterling, R. Harper.
Feb. 2020 Preprint A Cubical Language for Bishop Sets
J. Sterling, C. Angiuli, and D. Gratzer.


JFP To appear Higher-Order Functions and Brouwer's Thesis
Journal of Functional Programming, essays in honor of Robert Harper, to appear, 2020.
ICFP '19 Implementing a Modal Dependent Type Theory.
D. Gratzer, J. Sterling, and L. Birkedal.
International Conference on Functional Programming (ICFP), 2019.
Distinguished Paper Award.
FSCD '19 Cubical Syntax for Reflection-Free Extensional Equality.
J. Sterling, C. Angiuli, and D. Gratzer.
International Conference on Formal Structures for Computation and Deduction (FSCD), 2019.
Best Paper Award For Junior Researchers.
LFMTP '18 The RedPRL Proof Assistant.
C. Angiuli, E. Cavallo, K. Hou (Favonia), R. Harper, and J. Sterling.
International Workshop on Logical Frameworks and Meta-Languages: Theory and Practice (LFMTP), 2018.
Invited Paper
LICS '18 Guarded Computational Type Theory.
J. Sterling, R. Harper.
Proceedings of the 33rd Annual ACM/IEEE Symposium on Logic in Computer Science (LICS '18).
Apr. 2016 Dependent Types for Pragmatics.
D. McAdams, J. Sterling.
Redmond J., Pombo Martins O., Nepomuceno Fernández Á. (eds) Epistemology, Knowledge and the Impact of Interaction. Logic, Epistemology, and the Unity of Science, vol 38. Springer, Cham.

Selected Talks

(Conference talks listed with publications.)

Feb. 2021 Normalization for Cubical Type Theory
Pittsburgh's HoTT Seminar
Aug. 2020 Objective Metatheory of (Cubical) Type Theories
Thesis Proposal
Jun. 2020 redtt and the future of Cartesian cubical type theory.
Every Proof Assistant
Mar. 2020 Objective Metatheory of Dependent Type Theories.
Mar. 2020 (Cubical) Computability Structures.
MURI Grant Meeting
Jan. 2020 Gluing Models of Type Theory Along Flat Functors.
J. Sterling and C. Angiuli
CMU HoTT Seminar.
HoTT '19 Cubical Exact Equality and Categorical Gluing.
J. Sterling, C. Angiuli, and D. Gratzer.
International Conference on Homotopy Type Theory, 2019.
TYPES '19 XTT: Cubical Syntax for Extensional Equality (without equality reflection).
J. Sterling, C. Angiuli, and D. Gratzer.
TYPES, 2019.
Apr. 2019 Algebraic Type Theory and the Gluing Construction.
CMU HoTT Seminar.
Aug. 2018 redtt: implementing cartesian cubical type theory.
C. Angiuli, E. Cavallo, Favonia, R. Harper, A. Mőrtberg, and J. Sterling.
Dagstuhl Seminar 18341: Formalization of Mathematics in Type Theory.

Lectures and Research Notes

Oct. 2020
Notes A Synthetic Realignment Theorem
Apr. 2020 Notes An OK Version of Type Theory
Feb. 2020 Notes Connectives in Semantics of Type Theory
Fall 2017 Lecture Substructural Deduction
Guest lecture for Constructive Logic (15-317) at CMU.
Fall 2017 Lecture Implementing Inference Rules in Standard ML
Tutorial for Constructive Logic (15-317) as CMU.


Fall 2018 TA for Constructive Logic (15-317) with Karl Crary.
Fall 2017 TA for Constructive Logic (15-317) with Frank Pfenning.

Academic Service

I have served as an external reviewer or subreviewer for CSL (2021), ESOP (2021), FSCD (2019, 2020), FoSSaCS (2021), LICS (2017); and as a referee for MSCS.

I am a mentor for the SIGPLAN long-term mentoring program for programming languges researchers (SIGPLAN-M).

Awards and Honors

2019 ICFP '19 Distinguished Paper Award
2019 FSCD '19 Best Paper Award for Junior Researchers
2011 W.K. Pritchett Prize in Elementary Greek, UC Berkeley

Other Activities

Together with my co-hosts David Christiansen and Darin Morrison, I helped create The Type Theory Podcast.