Abstraction and Control for Shapely Nested Graph Transformation

Shapely nested graph transformation is the computational model for DIAPLAN, a language for programming with graphs representing diagrams that is currently being developed. The model supports nested structuring of graphs, structural graph types (shapes), and rules with graph variables. We extend this model by two concepts that are essential for programming: abstraction allows compound transformations to be named and parameterized; control allows the order of rule application to be specified. These concepts refine the computational model with respect to structuring and efficiency needs of a programming language while preserving its rule-based and graph-ical nature