JCT
2011
13 years 6 months ago
2011
The substitution closure of a pattern class is the class of all permutations obtained by repeated substitution. The principal pattern classes (those defined by a single restricti...
EJC
2008
13 years 11 months ago
2008
Abstract. A pattern class is a set of permutations closed under pattern involvement or, equivalently, defined by certain subsequence avoidance conditions. Any pattern class X which...