Sciweavers

TCS
2008
13 years 11 months ago
Simple permutations: Decidability and unavoidable substructures
We prove that it is decidable whether a finitely based permutation class contains infinitely many simple permutations, and establish an unavoidable substructure result for simple ...
Robert Brignall, Nikola Ruskuc, Vincent Vatter
COMBINATORICS
2007
49views more  COMBINATORICS 2007»
13 years 11 months ago
Wreath Products of Permutation Classes
A permutation class which is closed under pattern involvement may be described in terms of its basis. The wreath product construction X Y of two permutation classes X and Y is als...
Robert Brignall
CORR
2010
Springer
95views Education» more  CORR 2010»
13 years 11 months ago
Deciding the finiteness of the number of simple permutations contained in a wreath-closed class is polynomial
We present an algorithm running in time O(n log n) which decides if a wreathclosed permutation class Av(B) given by its finite basis B contains a finite number of simple permutati...
Frédérique Bassino, Mathilde Bouvel,...