Invalid L-line positions
Invalid L-line positions on the outside of a bend in the P-line.
When the P-line changes direction, the outside bend creates a triangular region in which all points on the L-line correspond to the same P-line point.
Figure 1: Invalid L-line positions
As can be seen in the above diagram, the greater the distance from the L-line to the P-line, the longer the inaccessible L-line section.
