In this thesis, we consider the problem of finding the L-kernel of a given rectilinear simple polygon P with n vertices.
Two points are said to be L-visible if they can be joined by a simple chain of at most two rectlinear line segments contained in P completely. The L-kernel $K_L$(P) of P is the locus of the points internal to P from which all vertices of P are L-visible.
We present an O(n) time and O(n) space algorithm for solving this problem, which is optimal.