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In a previous work, B\'ona and Pantone studied permutations that avoided all but one pattern of length $k$ that began with a length $k-1$ increasing subsequence. We draw the connection between that idea and distant patterns, first discussed…

Combinatorics · Mathematics 2025-11-27 Nicholas Van Nimwegen

Sequence classification has numerous applications in various fields. Despite extensive studies in the last decades, many challenges still exist, particularly in pattern-based methods. Existing pattern-based methods measure the…

Machine Learning · Computer Science 2023-10-23 Junjie Dong , Mudi Jiang , Lianyu Hu , Zengyou He

We improve and expand in two directions the theory of norms on complex matrices induced by random vectors. We first provide a simple proof of the classification of weakly unitarily invariant norms on the Hermitian matrices. We use this to…

Functional Analysis · Mathematics 2023-10-26 Ángel Chávez , Stephan Ramon Garcia , Jackson Hurley

A congruence of the weak order is simple if its quotientope is a simple polytope. We provide an alternative elementary proof of the characterization of the simple congruences in terms of forbidden up and down arcs. For this, we provide a…

Combinatorics · Mathematics 2026-05-07 Emily Barnard , Jean-Christophe Novelli , Vincent Pilaud

The aim of this paper is to introduce an algebraic structure on the set of all coalgebras with the same state space over the given type which allows us to present definitions of weak and delay bisimulation for coalgebras. Additionally, we…

Logic in Computer Science · Computer Science 2013-09-06 Tomasz Brengos

In this article, we introduce and study a new integer sequence referred to as the higher order Mersenne sequence. The proposed sequence is analogous to the higher order Fibonacci numbers and closely associated with the Mersenne numbers.…

Number Theory · Mathematics 2023-07-18 Kalika Prasad , Munesh Kumari , Rabiranjan Mohanta , Hrishikesh Mahato

Defant, Engen, and Miller defined a permutation to be uniquely sorted if it has exactly one preimage under West's stack-sorting map. We enumerate classes of uniquely sorted permutations that avoid a pattern of length three and a pattern of…

Combinatorics · Mathematics 2023-06-22 Hanna Mularczyk

In this paper we introduce and study a class of tableaux which we call permutation tableaux; these tableaux are naturally in bijection with permutations, and they are a distinguished subset of the Le-diagrams of Alex Postnikov. The…

Combinatorics · Mathematics 2007-05-23 Einar Steingrimsson , Lauren K. Williams

The recently introduced weakly disentangled representations proposed to relax some constraints of the previous definitions of disentanglement, in exchange for more flexibility. However, at the moment, weak disentanglement can only be…

Machine Learning · Computer Science 2022-09-13 Andrea Valenti , Davide Bacciu

We introduce two related notions of pattern enforcement in $(0,1)$-matrices: $Q$-forcing and strongly $Q$-forcing, which formalize distinct ways a fixed pattern $Q$ must appear within a larger matrix. A matrix is $Q$-forcing if every…

Combinatorics · Mathematics 2025-11-03 Lei Cao , Shen-Fu Tsai

This is the first contribution of a sequence of papers introducing the notions of $s$-weak order and $s$-permutahedra, certain discrete objects that are indexed by a sequence of non-negative integers $s$. In this first paper, we concentrate…

Combinatorics · Mathematics 2025-02-26 Cesar Ceballos , Viviane Pons

This paper reduces discontinuous parsing to sequence labeling. It first shows that existing reductions for constituent parsing as labeling do not support discontinuities. Second, it fills this gap and proposes to encode tree discontinuities…

Computation and Language · Computer Science 2020-10-05 David Vilares , Carlos Gómez-Rodríguez

A consecutive pattern in a permutation $\pi$ is another permutation $\sigma$ determined by the relative order of a subsequence of contiguous entries of $\pi$. Traditional notions such as descents, runs and peaks can be viewed as particular…

Combinatorics · Mathematics 2015-10-23 Sergi Elizalde

Deep learning models, such as wide neural networks, can be conceptualized as nonlinear dynamical physical systems characterized by a multitude of interacting degrees of freedom. Such systems in the infinite limit, tend to exhibit simplified…

Machine Learning · Computer Science 2024-01-09 Ori Shem-Ur , Yaron Oz

In this article, we study the relationship between notions of depth for sequences, namely, Bennett's notions of strong and weak depth, and deep $\Pi^0_1$ classes, introduced by the authors and motivated by previous work of Levin. For the…

Logic in Computer Science · Computer Science 2024-03-08 Laurent Bienvenu , Christopher P. Porter

There is a construction which lies at the heart of descent theory. The combinatorial aspects of this paper concern the description of the construction in all dimensions. The description is achieved precisely for strict n-categories and…

Category Theory · Mathematics 2007-05-23 Ross Street

We introduce the notion of the descent set polynomial as an alternative way of encoding the sizes of descent classes of permutations. Descent set polynomials exhibit interesting factorization patterns. We explore the question of when…

Combinatorics · Mathematics 2017-05-30 Denis Chebikin , Richard Ehrenborg , Pavlo Pylyavskyy , Margaret Readdy

We continue our study of semi-strict tricategories in which the only weakness is in vertical composition. We assemble the doubly-degenerate such tricategories into a 2-category, defining weak functors and transformations. We exhibit a…

Category Theory · Mathematics 2023-08-22 Eugenia Cheng , Alexander S. Corner

We study joint distributions of cycles and patterns in permutations written in standard cycle form. We explore both classical and generalised patterns of length 2 and 3. Many extensions of classical theory are achieved; bivariate generating…

Combinatorics · Mathematics 2007-11-05 Robert Parviainen

In this paper, we extend some classes of structured matrices to higher order tensors. We discuss their relationships with positive semi-definite tensors and some other structured tensors. We show that every principal sub-tensor of such a…

Spectral Theory · Mathematics 2014-06-24 Yisheng Song , Liqun Qi