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This observation, originally made by Bill Lawvere, has since then been expanded to other ‘’polynomial equations’‘ apart from TT 7T \simeq T^7 and other types than trees, revealing connections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


Revised on March 7, 2013 19:43:06 by Zoran Škoda (