Math.Sym.Class

A permutation class is a downset in the poset of permutations ordered by containment. This module provides definitions of some common classes.

Documentation

av231 :: Int -> [StPerm]

Av(231); also know as the stack sortable permutations.

vee :: Int -> [StPerm]

The V-class is Av(132, 231). It is so named because the diagram of a typical permutation in this class is shaped like a V.

wedge :: Int -> [StPerm]

The ∧-class is Av(213, 312). It is so named because the diagram of a typical permutation in this class is shaped like a wedge.

gt :: Int -> [StPerm]

The >-class is Av(132, 312). It is so named because the diagram of a typical permutation in this class is shaped like a >.

lt :: Int -> [StPerm]

The <-class is Av(213, 231). It is so named because the diagram of a typical permutation in this class is shaped like a <.

vorb :: Int -> [StPerm]

The union of vee, wedge, gt and lt; the orbit of a V under rotation