PSEG is a function of one argument--a region name which comes from REGIONLIST, as created by TOPOLOGIST. When it is done, the following data structure exists. *indicates that the data was already stored correctly when PSEG got it. REGIONLIST is a list of region names created by TOPOLOGIST. On the property list of each region are the following indicators: TYPE, OUTERBOUNDARY, NUCLEUS, HOLES, holes, NEIGHBORS, SHAPE, VERTIS, and SEGS. VERTEXLIST and SEGMENTLISTs are also discussed.
