The associahedron in 3 dimension, and James Stasheff. This
picture is taken from Bill Casselman’s article on the
associahedron. The article is entitled “Strange Associations”
and starts with ”There are many other polytopes that can be
described in purely combinatorial terms. Among the more curious
are the associahedra….” Dov Tamari as a young student at the
Hebrew University of Jerusalem. The associahedron (also known as
the Stasheff polytope) is a remarkable convex polytope first
described combinatorially by James Stasheff in 1963. The first
proof that it is indeed a polytope is attributed to John Milnor
(unpublished). The combinatorial structure was considered
independently by Dov Tamari who also asked for a realization as
a convex polytope, and such a realization was found by Mark
Haiman and Carl Lee. It was also constructed independently as a
special case of a much more general construction (called
¨secondary polytopes¨) by Israel Gelfand, Michael Kapranov, and
Andrei Zelevinsky. 4.1 Making polytopes from