Before revision: Given an orthogonal polygon with orthogonal holes, we devise a dynamic algorithm for guarding with vertex guards\cal \cal  , i.e., whenever orthogonal polygon is modified,\cal \cal  algorithm updates the set of vertex guards and their positions for guarding the modified orthogonal polygon\cal \cal  .
After revision: Given an orthogonal polygon with orthogonal holes, we devise a dynamic algorithm for guarding with vertex guards\cal \cal , i.e., whenever orthogonal polygon is modified,\cal P' is modified to result in another orthogonal polygonal domain\cal algorithm updates the set of vertex guards and their positions for guarding the modified orthogonal polygon\cal \cal .