Application of ER and CONGOO formalisms in a spatial database-reengineering project Roland Billen 1 , Dimos Pantazis 2 and Bernard Cornélis 3 1 Center for Geosciences, Department of Geography and Geomatics, University of Glasgow, Glasgow G12 8QQ, Scotland (UK), rbillen@geog.gla.ac.uk 2 Department of Surveying, School of Technological Applications, TEI (Institution of Technological Education of Athens), Samarinas 3, Sepolia 10443 Athens, Greece, pantdonz@otenet.gr 3 SPIRAL, Université de Liège, Belgium, cornber@yahoo.com