Tài liệu Phân loại các lớp học

Weak and strong sorting classes are pattern-closed classes that are also closed
downwards under the weak and strong orders on permutations. They are studied
using partial orders that capture both the subpermutation order and the weak or
strong order. In both cases they can be characterised by forbidden permutations in
the appropriate order. The connection with the corresponding forbidden permuta-
tions in pattern-closed classes is explored. Enumerative results are found in both
cases.