TopoGeo_AddPolygon — Adds a polygon to an existing topology using a tolerance and possibly splitting existing edges/faces.
integer TopoGeo_AddPolygon(varchar atopology, geometry apoly, float8 atolerance
Adds a polygon to an existing topology and return a set of face identifiers forming it up. The boundary of the given polygon will snap to existing nodes or edges within given tolerance. Existing edges and faces may be split by the boundary of the new polygon.