activity
20152026
most citedWilf collapse in permutation classes

1 citations · 2 across the 15 of their papers we have counts for

collaborators
Showing math.COShow all

11 papers · 1 filter

math.CO2026

Linear clique-width and modular decomposition

Robert Brignall, Michal Opler, Vincent Vatter

A hereditary class of graphs has bounded clique-width if and only if its prime members do, but this lifting property fails for linear clique-width. We prove that a hereditary class…

math.CO2025

Monadic Second-Order Logic of Permutations

Vít Jelínek, Michal Opler

Permutations can be viewed as pairs of linear orders, or more formally as models over a signature consisting of two binary relation symbols. This approach was adopted by Albert, Bo…

math.CO2023

The Hierarchy of Hereditary Sorting Operators

Vít Jelínek, Michal Opler, Jakub Pekárek

We consider the following general model of a sorting procedure: we fix a hereditary permutation class , which corresponds to the operations that the procedure is allow…

math.CO2023

Bounds on Functionality and Symmetric Difference -- Two Intriguing Graph Parameters

Pavel Dvořák, Lukáš Folwarczný, Michal Opler +3

Functionality () is a graph parameter that generalizes graph degeneracy defined by Alecu et al. [JCTB, 2021]. They research the relation of functionality to many othe…

math.CO2021

Griddings of permutations and hardness of pattern matching

Vít Jelínek, Michal Opler, Jakub Pekárek

We study the complexity of the decision problem known as Permutation Pattern Matching, or PPM. The input of PPM consists of a pair of permutations (the `text') and (the `pa…

math.CO2021

Bears with Hats and Independence Polynomials

Václav Blažej, Pavel Dvořák, Michal Opler

Consider the following hat guessing game. A bear sits on each vertex of a graph , and a demon puts on each bear a hat colored by one of colors. Each bear sees only the hat c…

math.CO2020

A Complexity Dichotomy for Permutation Pattern Matching on Grid Classes

Vít Jelínek, Michal Opler, Jakub Pekárek

Permutation Pattern Matching (PPM) is the problem of deciding for a given pair of permutations P and T whether the pattern P is contained in the text T. Bose, Buss and Lubiw showed…

math.CO2019

Two examples of Wilf-collapse

Michael Albert, Vít Jelínek, Michal Opler

Two permutation classes, the X-class and subpermutations of the increasing oscillation are shown to exhibit an exponential Wilf-collapse. This means that the number of distinct enu…

math.CO2019★ 1 cited

Wilf collapse in permutation classes

Michael Albert, Vít Jelínek, Michal Opler

For a hereditary permutation class , we say that two permutations and of are Wilf-equivalent in , if has the same numb…

math.CO2017

Splittability and 1-amalgamability of permutation classes

Vít Jelínek, Michal Opler

A permutation class is splittable if it is contained in a merge of two of its proper subclasses, and it is 1-amalgamable if given two permutations and in , each with…

math.CO2015★ 1 cited

Major index distribution over permutation classes

Michal Opler

For a permutation the major index of is the sum of all indices such that . It is well known that the major index is equidistributed with the number of in…