,
Robin Piedeleu
,
Alexandra Silva
,
Fabio Zanasi
Creative Commons Attribution 4.0 International license
We extend the synthetic theories of discrete and Gaussian categorical probability by introducing a diagrammatic calculus for reasoning about hybrid probabilistic models in which continuous random variables, conditioned on discrete ones, follow a multivariate Gaussian distribution. This setting includes important families of distributions such as Gaussian mixtures, where each Gaussian component is selected according to a discrete variable. We develop a string diagrammatic syntax for distributions of this type, give it a compositional semantics, and equip it with a sound and complete equational theory that characterises when two mixtures represent the same distribution.
@InProceedings{torresruiz_et_al:LIPIcs.CSL.2026.11,
author = {Torres-Ruiz, Mateo and Piedeleu, Robin and Silva, Alexandra and Zanasi, Fabio},
title = {{A Complete Diagrammatic Calculus for Conditional Gaussian Mixtures}},
booktitle = {34th EACSL Annual Conference on Computer Science Logic (CSL 2026)},
pages = {11:1--11:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-411-6},
ISSN = {1868-8969},
year = {2026},
volume = {363},
editor = {Guerrini, Stefano and K\"{o}nig, Barbara},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.CSL.2026.11},
URN = {urn:nbn:de:0030-drops-254358},
doi = {10.4230/LIPIcs.CSL.2026.11},
annote = {Keywords: String diagrams, Category theory, Mixture models, Probability theory}
}