199 shell shows prime shells in red and other
shells in green. It is interesting to
note where the exclusion lines of prime shells are subsumed by green exclusion
lines. In other words, when the exclusion
line of a prime shell, which is red, coincides with the exclusion of a
non-prime shell further out, whereupon it becomes green. This is simply a concequence of the way that
the computer generates the images. You
could imagine the original red line as lying, unseen, underneath the overlaying
green line. All exclusion lines extend
to infinity, even if this is not shown on the diagrams.