The Polynomial Hierarchy and $ω$-categorical CSPs

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Pro, Santiago Guzmán, Rydval, Jakub
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911626585702400
author Pro, Santiago Guzmán
Rydval, Jakub
author_facet Pro, Santiago Guzmán
Rydval, Jakub
contents In 2008, Bodirsky and Grohe showed that for every $Π_n^{\mathrm{P}}$-level of the Polynomial Hierarchy (PH) there are $ω$-categorical Constraint Satisfaction Problems (CSPs) complete for this level. We show that, in fact, there are $ω$-categorical CSPs complete for any level of the PH. To this end, we use a recent result of Bodirsky, Knäuer, and Rudolph for constructing $ω$-categorical CSPs from sentences of Monadic Second-Order logic (MSO) with certain preservation properties. As a secondary contribution, we develop a new tool for producing MSO sentences satisfying said preservation properties.
format Preprint
id arxiv_https___arxiv_org_abs_2604_24539
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle The Polynomial Hierarchy and $ω$-categorical CSPs
Pro, Santiago Guzmán
Rydval, Jakub
Logic in Computer Science
03B70
In 2008, Bodirsky and Grohe showed that for every $Π_n^{\mathrm{P}}$-level of the Polynomial Hierarchy (PH) there are $ω$-categorical Constraint Satisfaction Problems (CSPs) complete for this level. We show that, in fact, there are $ω$-categorical CSPs complete for any level of the PH. To this end, we use a recent result of Bodirsky, Knäuer, and Rudolph for constructing $ω$-categorical CSPs from sentences of Monadic Second-Order logic (MSO) with certain preservation properties. As a secondary contribution, we develop a new tool for producing MSO sentences satisfying said preservation properties.
title The Polynomial Hierarchy and $ω$-categorical CSPs
topic Logic in Computer Science
03B70
url https://arxiv.org/abs/2604.24539