Recursive graphs (R-graphs) are modified for use Is a formalism to represent evolving drawings spanning various levels of detail, and store them in a database. A separation of the structural information and the physical image information is advocated. To guarantee maximum flexibility, the physical image information is represented in relational form, and for consistency and ease of manipulation, the R-graphs containing the structural information are mapped into normalized relations. Major design aspects for implementation are considered, such as, the feasibility of a mapping into binary associations and the drawing generation strategy. Binary associations are an adequate model to express conceptual schemata and are often used as input format for existing computer aided database dsesign packages. As an illustration of the propose formalism, the evolution through three levels of detail in nested drawings handled during the design of chemical process plants is demonstrated.
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