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An overlap representation is an assignment of sets to the vertices of a graph in such a way that two vertices are adjacent if and only if the sets assigned to them overlap. The overlap number of a graph is the minimum number of elements…

Discrete Mathematics · Computer Science 2010-08-17 Bill Rosgen , Lorna Stewart

Tolerance graphs model interval relations in such a way that intervals can tolerate a certain degree of overlap without being in conflict. This subclass of perfect graphs has been extensively studied, due to both its interesting structure…

Computational Complexity · Computer Science 2010-02-03 George B. Mertzios , Ignasi Sau , Shmuel Zaks

A graph $G=(V,E)$ is said to be word-representable if there exists a word $w$ over the alphabet $V$ such that two distinct letters $x,y\in V$ alternate in $w$ if and only if $xy \in E$. Word-representable graphs form a well-studied graph…

Combinatorics · Mathematics 2026-05-26 Suchanda Roy , Ramesh Hariharasubramanian

Graph grammars extend the theory of formal languages in order to model distributed parallelism in theoretical computer science. We show here that to certain classes of context-free and context-sensitive graph grammars one can associate a…

Formal Languages and Automata Theory · Computer Science 2015-03-02 Matilde Marcolli , Alexander Port

Hypergraph categories have been rediscovered at least five times, under various names, including well-supported compact closed categories, dgs-monoidal categories, and dungeon categories. Perhaps the reason they keep being reinvented is…

Category Theory · Mathematics 2019-01-23 Brendan Fong , David I Spivak

Graphs and various graph-like combinatorial structures, such as preorders and hypergraphs, are ubiquitous in programming. This paper focuses on representing graphs in a purely functional programming language like Haskell. There are several…

Programming Languages · Computer Science 2022-02-21 Andrey Mokhov

Whereas string diagrams for strict monoidal categories are well understood, and have found application in several fields of Computer Science, graphical formalisms for non-strict monoidal categories are far less studied. In this paper, we…

Category Theory · Mathematics 2024-11-06 Paul Wilson , Dan Ghica , Fabio Zanasi

Consider a graph G = G(k,d,s) with vertex set the set of all k-letter words over an alphabet of size d. An edge e = vw is in E iff v is distinct from w and the last(first) k-s letters of v are identical to the first(last) k-s letters of w.…

Combinatorics · Mathematics 2007-05-23 Anant Godbole , Debra Knisley , Rick Norwood

We present a new and powerful algebraic framework for graph rewriting, based on drags, a class of graphs enjoying a novel composition operator. Graphs are embellished with roots and sprouts, which can be wired together to form edges. Drags…

Logic in Computer Science · Computer Science 2024-06-28 Nachum Dershowitz , Jean-Pierre Jouannaud , Fernando Orejas

A graph is 1-planar if it can be drawn on a plane so that each edge is crossed by at most one other edge. In this paper, we first give a useful structural theorem for 1-planar graphs, and then apply it to the list edge and list total…

Combinatorics · Mathematics 2019-12-17 Xin Zhang , Bei Niu , Jiguo Yu

Determining whether two graphs are structurally identical is a fundamental problem with applications spanning mathematics, computer science, chemistry, and network science. Despite decades of study, graph isomorphism remains a challenging…

Computational Physics · Physics 2026-04-10 Sara Najem , Amer E. Mouawad

Knowledge graphs can represent information about the real-world using entities and their relations in a structured and semantically rich manner and they enable a variety of downstream applications such as question-answering, recommendation…

Computation and Language · Computer Science 2023-05-16 Hanieh Khorashadizadeh , Nandana Mihindukulasooriya , Sanju Tiwari , Jinghua Groppe , Sven Groppe

A categorical formalism for directed graphs is introduced, featuring natural notions of morphisms and subgraphs, and leading to two elementary descriptions of the free-properad monad, first in terms of presheaves on elementary graphs,…

Quantum Algebra · Mathematics 2016-10-04 Joachim Kock

Bimonoidal categories (also known as rig categories) are categories with two monoidal structures, one of which distributes over the other. We formally define sheet diagrams, a graphical calculus for bimonoidal categories that was informally…

Category Theory · Mathematics 2020-12-22 Cole Comfort , Antonin Delpeuch , Jules Hedges

Large language models (LLMs), such as GPT4 and LLaMA, are creating significant advancements in natural language processing, due to their strong text encoding/decoding ability and newly found emergent capability (e.g., reasoning). While LLMs…

Computation and Language · Computer Science 2024-11-22 Bowen Jin , Gang Liu , Chi Han , Meng Jiang , Heng Ji , Jiawei Han

Visual language is a system of communication that conveys information through symbols, shapes, and spatial arrangements. Diagrams are a typical example of a visual language depicting complex concepts and their relationships in the form of…

Computation and Language · Computer Science 2025-05-27 Yifan Hou , Buse Giledereli , Yilei Tu , Mrinmaya Sachan

Regular logic can be regarded as the internal language of regular categories, but the logic itself is generally not given a categorical treatment. In this paper, we understand the syntax and proof rules of regular logic in terms of the free…

Category Theory · Mathematics 2019-06-21 Brendan Fong , David I Spivak

In graph learning, maps between graphs and their subgraphs frequently arise. For instance, when coarsening or rewiring operations are present along the pipeline, one needs to keep track of the corresponding nodes between the original and…

Machine Learning · Computer Science 2023-02-01 Marco Pegoraro , Riccardo Marin , Arianna Rampini , Simone Melzi , Luca Cosmo , Emanuele Rodolà

E-graphs are a data structure that compactly represents equivalent expressions. They are constructed via the repeated application of rewrite rules. Often in practical applications, conditional rewrite rules are crucial, but their…

Data Structures and Algorithms · Computer Science 2023-08-16 Samuel Coward , George A. Constantinides , Theo Drane

Graphical languages are symmetric monoidal categories presented by generators and equations. The string diagrams notation allows to transform numerous axioms into low dimension topological rules we are comfortable with as three dimensional…

Category Theory · Mathematics 2021-07-06 Titouan Carette