Summary

Description Tamari lattice.svg	English: The Hasse diagram of a Tamari lattice . Français : Le diagramme de Hasse d'un treillis de Tamari
Date	22 November 2008
Source	Own work
Author	David Eppstein
Permission ( Reusing this file )	Public domain Public domain false false I, the copyright holder of this work, release this work into the public domain . This applies worldwide. In some countries this may not be legally possible; if so: I grant anyone the right to use this work for any purpose , without any conditions, unless such conditions are required by law.

Overview

The associahedron K5 has C ₄ = 14 vertices, 21 edges and T ₄ −1 = 9 faces.
Each one of the faces corresponds to a 2-subset of {1,2,3,4,5} except {1,5}. Faces whose 2-subsets overlap do not touch.
(Overlap would mean that an element in one set is between the elements of the other, like with {1,3} and {2,4}.)
An edge or vertex corresponds to a set that contains the 2-subsets of the faces that meet in this edge or vertex.

	Triangulated hexagons	Binary trees	Sets of 2-subsets	Ovals	Parentheses
Vertices (and edges)
Faces