Return the complement of the interior of the cap. A cap and its
complement have the same boundary but do not share any interior points.
The complement operator is not a bijection because the complement of a
singleton cap (containing a single point) is the same as the complement
of an empty cap.
Return the complement of the interior of the cap. A cap and its complement have the same boundary but do not share any interior points. The complement operator is not a bijection because the complement of a singleton cap (containing a single point) is the same as the complement of an empty cap.