First-order model checking on structurally sparse graph classes

J Dreier, N Mählmann, S Siebertz - Proceedings of the 55th Annual ACM …, 2023 - dl.acm.org
A class of graphs is structurally nowhere dense if it can be constructed from a nowhere
dense class by a first-order transduction. Structurally nowhere dense classes vastly …

Flip-width: Cops and robber on dense graphs

S Toruńczyk - 2023 IEEE 64th Annual Symposium on …, 2023 - ieeexplore.ieee.org
We define new graph parameters, called flip-width, that generalize treewidth, degeneracy,
and generalized coloring numbers for sparse graphs, and clique-width and twin-width for …

[PDF][PDF] Flip-breakability: A combinatorial dichotomy for monadically dependent graph classes

J Dreier, N Mählmann, S Toruńczyk - Proceedings of the 56th Annual …, 2024 - dl.acm.org
A conjecture in algorithmic model theory predicts that the model-checking problem for first-
order logic is fixed-parameter tractable on a hereditary graph class if and only if the class is …

Flipper games for monadically stable graph classes

J Gajarský, N Mählmann, R McCarty… - arXiv preprint arXiv …, 2023 - arxiv.org
A class of graphs $\mathscr {C} $ is monadically stable if for any unary expansion $\widehat
{\mathscr {C}} $ of $\mathscr {C} $, one cannot interpret, in first-order logic, arbitrarily long …

Compound logics for modification problems

FV Fomin, PA Golovach, I Sau, G Stamoulis… - ACM Transactions on …, 2023 - dl.acm.org
We introduce a novel model-theoretic framework inspired from graph modification and
based on the interplay between model theory and algorithmic graph minors. The core of our …

Model-checking for first-order logic with disjoint paths predicates in proper minor-closed graph classes

PA Golovach, G Stamoulis, DM Thilikos - … of the 2023 Annual ACM-SIAM …, 2023 - SIAM
The disjoint paths logic, FOL+ DP, is an extension of First-Order Logic (FOL) with the extra
atomic predicate dp k (x 1, y 1,…, xk, yk), expressing the existence of internally vertex …

Parameterizing the quantification of CMSO: model checking on minor-closed graph classes

I Sau, G Stamoulis, DM Thilikos - arXiv preprint arXiv:2406.18465, 2024 - arxiv.org
Given a graph $ G $ and a vertex set $ X $, the annotated treewidth tw $(G, X) $ of $ X $ in $
G $ is the maximum treewidth of an $ X $-rooted minor of $ G $, ie, a minor $ H $ where the …

Indiscernibles and flatness in monadically stable and monadically NIP classes

J Dreier, N Mählmann, S Siebertz… - 50th International …, 2023 - drops.dagstuhl.de
Monadically stable and monadically NIP classes of structures were initially studied in the
context of model theory and defined in logical terms. They have recently attracted attention …

Indiscernibles and wideness in monadically stable and monadically NIP classes

J Dreier, N Mählmann, S Siebertz… - arXiv preprint arXiv …, 2022 - arxiv.org
An indiscernible sequence $(\bar a_i) _ {1\leq i\leq n} $ in a structure is an ordered
sequence of tuples of elements which is very homogeneous in the sense that any two finite …

Canonical decompositions in monadically stable and bounded shrubdepth graph classes

P Ohlmann, M Pilipczul, S Toruńczyk… - arXiv preprint arXiv …, 2023 - arxiv.org
We use model-theoretic tools originating from stability theory to derive a result we call the
Finitary Substitute Lemma, which intuitively says the following. Suppose we work in a stable …