... 1987 An Analysis of Geometric Modeling in Database Systems Conclusions In the first part of this paper we investigated the requirements imposed on database management systems by computer-aided manufacturing ... allows the engineer to specify and manipulate real-world objects interactively ACM Computing Surveys, Vol 19, No 1, March 1987 An Analysis of Geometric Modeling in Database Systems Figure Integrated ... ACM Computing Surveys, Vol 19, No 1, March 1987 An Analysis of Geometric Modeling in Database Systems l 85 Since we allow an abstract data type to be any NF2 object, it is, in particular,...