“…Example "b2" the intersection of the sphere h1 and the cylinder g1 ( = PP = EW[ [1]]={500, 0, 0}. Using the virtual algorithm with startpoint E1 P and monotonic direction x y z {S ,S ,S }=Sign[ EG[ [6]] -EW[ [1]]]={-1,1,1}, the next LSD point is the point S2 P = {500, 1, 1}. So, the new path is Segsb2 equals {EG[ [1]], EW[ [1]] , S2 P , EG[ [6]]}.…”