User blog comment:Mh314159/YIP notation/@comment-35470197-20190704230823/@comment-39585023-20190705021254

Thank you! Hmm, I thought I had used [a,2] to recurse [a,3] and in fact there is a contradition here:

"Start with the 2D expression [a,2]. This is the base expression and the edge length, or X0.

Use this expression to determine the edge length in a similarly constructed 2D expression, which we will call expression X1. In other words, if X 0 = [a,1], then X n+1 = [X n ,1] and [a,3] = X[a,2].

The statement about the starting expression and edge length contradicts the underlined in terms of expression type X, which I have now corrected. I think this happened when I redefined [a,b] to stop at b=1 and not b=0 so as to more clearly correspond to dimensionality, and I missed readjusting one of the expressions.

Thanks for the instruction! I may never reach the levels you described, but I still find these things interesting.