Logic for differential equations
Sound and complete reasoning about continuous and hybrid systems through differential dynamic logic.
Mathematical logic · Carnegie Mellon University
Hi! I’m Long, a PhD student in mathematical logic at Carnegie Mellon University, advised by André Platzer. I study the logical foundations of differential equations through differential dynamic logic.
I am also interested in computer-assisted mathematics, particularly the application of automated reasoning tools to combinatorial problems. I have previously worked on classifying the complexity of geometric properties of Banach spaces.
Feel free to get in touch!
Research
Sound and complete reasoning about continuous and hybrid systems through differential dynamic logic.
SAT solving and automated reasoning as tools for discovering and verifying mathematical constructions.
The algorithmic content of analysis, including the geometry and structure of computable Banach spaces.
A complete axiomatization for open properties of linear differential equations on compact initial sets and time horizons, reducing proofs to linear real arithmetic.
@inproceedings{qian2027linear,
title = {Linear Axiomatization of Linear Differential Equations},
author = {Long Qian and André Platzer},
year = {2027},
booktitle = {EACSL Annual Conference on Computer Science Logic (CSL)},
note = {Accepted, to appear}
}
A complete axiomatization of open safety, open liveness, and existence properties for compact initial value problems, connecting symbolic proofs with rigorous numerical error bounds.
@article{platzer2025compact,
title = {Axiomatization of Compact Initial Value Problems: Open Properties},
author = {André Platzer and Long Qian},
year = {2025},
journal = {Journal of the ACM},
volume = {72},
number = {6},
pages = {41:1--41:51},
doi = {10.1145/3763228},
eprint = {2410.13836},
archivePrefix = {arXiv}
}
Embedding rotational symmetry into SAT encodings to discover new point configurations satisfying constraints in discrete geometry.
@inproceedings{subercaseaux2025symmetric,
title = {Automated Symmetric Constructions in Discrete Geometry},
author = {Bernardo Subercaseaux and Ethan Mackey and Long Qian and Marijn Heule},
year = {2025},
booktitle = {International Conference on Intelligent Computer Mathematics (CICM)},
pages = {29--47},
doi = {10.1007/978-3-032-07021-0_3},
eprint = {2506.00224},
archivePrefix = {arXiv}
}