,
Marlene Gründel
,
Christian Komusiewicz
,
Nils Morawietz
,
Till Tantau
Creative Commons Attribution 4.0 International license
A relation modification problem gets a logical structure and a natural number k as input and asks whether k modifications of the structure suffice to make it satisfy a predefined property. We provide a complete classification of the classical and parameterized complexity of relation modification problems - the latter w. r. t. the modification budget k - based on the descriptive complexity of the respective target property. We consider different types of logical structures on which modifications are performed: Whereas monadic structures and undirected graphs without self-loops each yield their own complexity landscapes, we find that modifying undirected graphs with self-loops, directed graphs, or arbitrary logical structures is equally hard w. r. t. quantifier patterns.
Moreover, we observe that all classes of problems considered in this paper are subject to a strong dichotomy in the sense that they are either very easy to solve (that is, they lie in para-AC^{0↑} or TC^0) or intractable (that is, they contain W[2]-hard or NP-hard problems).
@InProceedings{chudigiewitsch_et_al:LIPIcs.MFCS.2026.93,
author = {Chudigiewitsch, Florian and Gr\"{u}ndel, Marlene and Komusiewicz, Christian and Morawietz, Nils and Tantau, Till},
title = {{The Descriptive Complexity of Relation Modification Problems}},
booktitle = {51st International Symposium on Mathematical Foundations of Computer Science (MFCS 2026)},
pages = {93:1--93:17},
series = {Leibniz International Proceedings in Informatics (LIPIcs)},
ISBN = {978-3-95977-442-0},
ISSN = {1868-8969},
year = {2026},
volume = {386},
editor = {Kouck\'{y}, Michal and Petrișan, Daniela},
publisher = {Schloss Dagstuhl -- Leibniz-Zentrum f{\"u}r Informatik},
address = {Dagstuhl, Germany},
URL = {https://drops.dagstuhl.de/entities/document/10.4230/LIPIcs.MFCS.2026.93},
URN = {urn:nbn:de:0030-drops-274752},
doi = {10.4230/LIPIcs.MFCS.2026.93},
annote = {Keywords: graph problems, descriptive complexity, edge modification, parameterized complexity, circuit complexity}
}