,
Arnaud Durand
,
Rui Li
Creative Commons Attribution 4.0 International license
The paper proposes an implicit (i.e., machine-independent) complexity approach to studying computation by polynomial-size, constant-depth circuits with gates counting modulo a constant through the lens of discrete ordinary differential equations (ODEs). So far, recursion-theoretic characterizations have been provided for functions computed by circuits of constant depth, including gates counting modulo 2 and 6 only (i.e., for the classes FAC⁰[2] and FAC⁰[6], resp.). In this paper, it is shown that considering ODE schemas, rather than bounded recursion, allows for a more fine-grained analysis, leading to (uniform) characterizations for all classes FAC⁰[n] (n ∈ ℕ), i.e. functions computed by circuits including counting modulo n gates. Inspired by the syntactic form of the ODE schemas, we go further in this direction and present first-order bounded theories for capturing provably total functions in each of these classes.
@InProceedings{antonelli_et_al:LIPIcs.ICALP.2026.162,
author = {Antonelli, Melissa and Durand, Arnaud and Li, Rui},
title = {{Recursion and Proof Theoretical Characterizations of Small Circuit Classes with Modulo Counting via Discrete Differential Equations}},
booktitle = {53rd International Colloquium on Automata, Languages, and Programming (ICALP 2026)},
pages = {162:1--162:19},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-428-4},
ISSN = {1868-8969},
year = {2026},
volume = {374},
editor = {Bhattacharya, Sayan and Nanongkai, Danupon and Benedikt, Michael and Puppis, Gabriele},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.ICALP.2026.162},
URN = {urn:nbn:de:0030-drops-265501},
doi = {10.4230/LIPIcs.ICALP.2026.162},
annote = {Keywords: Implicit complexity, circuit complexity, small circuit classes with counting, discrete ODEs, recursion theory, bounded arithmetic}
}