seven trees in one

Seven trees in one


There is a natural bijection between the set of finite binary trees and the set of seven-tuples of such.

This observation, originally made by Bill Lawvere, has since then been expanded to other ‘’polynomial equations’‘ apart from TT 7T \simeq T^7 and other types than trees, revealing connections between type theory and calculus.


Last revised on March 7, 2013 at 19:43:06. See the history of this page for a list of all contributions to it.