arc of simple curve < Je, (drawn splintered fig. 4), joining P, and 
P,, not cutting the are of W, enclosed between P, and # neither 
the are of Y, enclosed between P, and aw. On this are of simple 
curve we represent the first resp. the last point of intersection with 
y by A, resp. Li, 
By the skeleton arc R,P,G, we shall understand the are of simple 
curve obtained by following from Z?, first the path R,P,, then W,, 
up to its point of intersection with ZG, and finally the path ZG, 
from that point of intersection to (@,. 
This skeleton are 2, P,G', does not meet its image skeleton arc 
0,7,7,, Which image skeleton are cuts neither the path w nor the 
path £,G,, whilst the circumference segments ,G, and 9,7, lie 
outside each other. 
The ares PG, and 0,77, we join by an are of simple curve AL, 
(see fig. 5), belonging to an approximating polygonal line Pe rp), 
J, 
Fig. 5. 
and abroad from its endpoints cutting neither the skeleton arcs 
R,P,G, and o,7,7,, nor the paths w and £,G,. 
The are K,L, we divide into such partial ares, that on each of 
them the distance of the endpoints lies between 4te, and 12e, and 
the distance of two arbitrary points does not exceed 24¢,. From the 
d 3 
endpoints of these partial ares we draw to p straight paths < Pe 
among which we regard each pair of two successive ones, together 
with the partial are of K,L, connecting them, again as a skeleton are. 
