User blog comment:Wythagoras/Dollar function: final version/@comment-5029411-20131114223319

My extension is faster than your extension!

[a,b] = [a]b+1.

[0,0,1]m+1 = [0,[0,...][0,0,1]m][0,0,1]m.

[m+1 @] = [m @]...[m @].

[0,m+1,1] = [[...,m,1],m,1].

[0,0,2] = [0,[0,...,1],1].

[0,0,m+1] = [0,[0,...,m],m].

[0,0,0,1] = [0,0,[0,0,...]].

[0 -> 1] = [n,n...n,n].

[0 -> 2] = [n,n...n,n -> 1].