All Ternary Permutation Constraint Satisfaction Problems Parameterized Above Average Have Kernels with Quadratic Numbers of Variables
arXiv:1004.1956
Abstract
A ternary Permutation-CSP is specified by a subset of the symmetric group . An instance of such a problem consists of a set of variables and a multiset of constraints, which are ordered triples of distinct variables of The objective is to find a linear ordering of that maximizes the number of triples whose ordering (under ) follows a permutation in . We prove that all ternary Permutation-CSPs parameterized above average have kernels with quadratic numbers of variables.