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Graph data model and graph databases are very popular in various areas such as bioinformatics, semantic web, and social networks. One specific problem in the area is a path querying with constraints formulated in terms of formal grammars.…

Databases · Computer Science 2023-02-21 Semyon Grigorev , Anastasiya Ragozina

We extend Edmonds' Branching Theorem to locally finite infinite digraphs. As examples of Oxley or Aharoni and Thomassen show, this cannot be done using ordinary arborescences, whose underlying graphs are trees. Instead we introduce the…

Combinatorics · Mathematics 2020-04-06 J. Pascal Gollin , Karl Heuer

In the first paper of the Graph Minors series [JCTB '83], Robertson and Seymour proved the Forest Minor theorem: the $H$-minor-free graphs have bounded pathwidth if and only if $H$ is a forest. In recent years, considerable effort has been…

Combinatorics · Mathematics 2025-12-02 Édouard Bonnet , Benjamin Duhamel , Robert Hickingbotham

We consider the task of pixel-wise semantic segmentation given a small set of labeled training images. Among two of the most popular techniques to address this task are Decision Forests (DF) and Neural Networks (NN). In this work, we…

Computer Vision and Pattern Recognition · Computer Science 2018-08-14 David L. Richmond , Dagmar Kainmueller , Michael Y. Yang , Eugene W. Myers , Carsten Rother

In this work, we translate at the level of decorated trees some of the crucial arguments which have been used in arXiv:2112.10739 for proposing a diagram-free approach for the convergence of the model in Regularity Structures. This allows…

Probability · Mathematics 2023-10-05 Yvain Bruned , Usama Nadeem

In 1966, Cummins introduced the "tree graph": the tree graph $\mathbf{T}(G)$ of a graph $G$ (possibly infinite) has all its spanning trees as vertices, and distinct such trees correspond to adjacent vertices if they differ in just one edge,…

Combinatorics · Mathematics 2021-06-21 Suresh Dara , S. M. Hegde , Venkateshwarlu Deva , S. B. Rao , Thomas Zaslavsky

Context-free S grammars are introduced, for arbitrary (storage) type S, as a uniform framework for recursion-based grammars, automata, and transducers, viewed as programs. To each occurrence of a nonterminal of a context-free S grammar an…

Formal Languages and Automata Theory · Computer Science 2014-08-05 Joost Engelfriet

The first-order theory of finite and infinite trees has been studied since the eighties, especially by the logic programming community. Following Djelloul, Dao and Fr\"uhwirth, we consider an extension of this theory with an additional…

Logic in Computer Science · Computer Science 2020-08-10 Fabian Zaiser , C. -H. Luke Ong

For a set-endofunctor $F$, we extend the notion of universal $F$-coalgebras to $F$-graphs. These generalized coalgebras are models for various types of graphs, such as (un)directed (hyper)graphs, relational structures or fuzzy graphs. The…

Combinatorics · Mathematics 2015-08-11 Christian Jäkel

Many recent works address the question of characterizing induced obstructions to bounded treewidth. In 2022, Lozin and Razgon completely answered this question for graph classes defined by finitely many forbidden induced subgraphs. Their…

Connection matrices for graph parameters with values in a field have been introduced by M. Freedman, L. Lov{\'a}sz and A. Schrijver (2007). Graph parameters with connection matrices of finite rank can be computed in polynomial time on graph…

Combinatorics · Mathematics 2014-05-13 Nadia Labai , Johann A. Makowsky

L-systems can be made to model and create simulations of many biological processes, such as plant development. Finding an L-system for a given process is typically solved by hand, by experts, in a massively time-consuming process. It would…

Quantum Physics · Physics 2025-07-02 Ali Lotfi , Ian McQuillan , Steven Rayan

To most mathematicians and computer scientists the word ``tree'' conjures up, in addition to the usual image, the image of a connected graph with no circuits. In the last few years various types of trees have been the subject of much…

Group Theory · Mathematics 2016-09-06 John W. Morgan

Tangle-tree theorems are an important tool in structural graph theory, and abstract separation systems are a very general setting in which tangle-tree theorems can still be formulated and proven. For infinite abstract separation systems, so…

Combinatorics · Mathematics 2023-09-14 Ann-Kathrin Elm , Hendrik Heine

This paper presents the novel `uniqueness tree' algorithm, as one possible method for determining whether two finite, undirected graphs are isomorphic. We prove that the algorithm has polynomial time complexity in the worst case, and that…

Discrete Mathematics · Computer Science 2016-06-22 Jonathan Gorard

This paper considers synchronous discrete-time dynamical systems on graphs based on the threshold model. It is well known that after a finite number of rounds these systems either reach a fixed point or enter a 2-cycle. The problem of…

Discrete Mathematics · Computer Science 2022-02-04 Volker Turau

Tree-like tableaux are certain fillings of Ferrers diagrams originally introduced by Aval et al., which are in simple bijections with permutation tableaux coming from Postnikov's study of totally nonnegative Grassmanian and alternative…

Combinatorics · Mathematics 2023-06-22 Sherry H. F. Yan , Robin D. P. Zhou

Motivated by extreme value theory, max-linear Bayesian networks have been recently introduced and studied as an alternative to linear structural equation models. However, for max-linear systems the classical independence results for…

Statistics Theory · Mathematics 2022-03-01 Carlos Améndola , Claudia Klüppelberg , Steffen Lauritzen , Ngoc Tran

Tree sets are posets with additional structure that generalize tree-like objects in graphs, matroids, or other combinatorial structures. They are a special class of abstract separation systems. We study infinite tree sets and how they…

Combinatorics · Mathematics 2025-05-16 Jay Lilian Kneip

Context-free session types provide a typing discipline for recursive structured communication protocols on bidirectional channels. They overcome the restriction of regular session type systems to tail recursive protocols. This extension…

Programming Languages · Computer Science 2022-08-03 Bernardo Almeida , Andreia Mordido , Peter Thiemann , Vasco T. Vasconcelos