NETHERLANDS GEODETIC COMMISSION PUBLICATIONS ON GEODESY NEW SERIES ISSN0165 1706 NUMBER 43 METHODS FORTHE GENERALIZATION OF GEO.DATABASES EDITED BY MARTIEN MOLENAAR 1996 NEDERLANDSECOMMISSIE VOOR GEODESIE, THIJSSEWEG 11,2629 JA DELFT, THE NETHERLANDS TEL. (3 1)-(0) I s -27 82819, FAX (3 l)-(0)l s-27 827 4s