Theory: It is impossible to cross all the bridges without recrossing at least one: in such a network some retracing is inevitable whenever there are three or more points at which an odd number of pathways converge (Leonard Euler 1707- 1783)
A map charting all the surfaces of the artist's skin that he could see directly. Starting with his left hand, he gridded off his palm and depicted it. He then wound up his hand, arm, and across the rest of his body. Mapping the body.