File:Tamari lattice, hexagons.svg

DescriptionTamari lattice, hexagons.svg	The associahedron of order 4 (or K5), the Hasse diagram of the Tamari lattice of order 4, with triangulated hexagons corresponding to binary trees
Source	Own work
Author	Watchduck You can name the author as "T. Piesk", "Tilman Piesk" or "Watchduck".
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The associahedron K5 has C₄ = 14 vertices, 21 edges and T₄−1 = 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