A hilbert curve of order 5 which is traversed repeatedly to emphasize the maze. The view enforced on you through this picture is an iterative one: We traverse the curve one edge after the other. Needless to tell, this gives a very confusing and complicated understanding of the curve. Below, we will explain the curve in recursive terms. It turns out that this will be key to understanding the curve. Relative to the Scheme program shown later, this curve is produced by the call (hilbert 5 'up) .