nLab seven trees in one

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This observation, originally made by Bill Lawvere, has since then been expanded to other “polynomial equations” apart from TT 7T \simeq T^7 and other types than trees, revealing connections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 June 1, 2021 at 16:14:21. See the history of this page for a list of all contributions to it.