2 research outputs found
Graph Rewriting and Relabeling with PBPO+
We extend the powerful Pullback-Pushout (PBPO) approach for graph rewriting
with strong matching. Our approach, called \pbpostrong, exerts more control
over the embedding of the pattern in the host graph, which is important for a
large class of graph rewrite systems. In addition, we show that \pbpostrong is
well-suited for rewriting labeled graphs and certain classes of attributed
graphs. For this purpose, we employ a lattice structure on the label set and
use order-preserving graph morphisms. We argue that our approach is simpler and
more general than related relabeling approaches in the literature.Comment: 20 pages, accepted to the International Conference on Graph
Transformation 2021 (ICGT 2021
The Pullback-Pushout approach to algebraic graph transformation
Some recent algebraic approaches to graph transformation include a pullback construction involving the match, that allows one to specify the cloning of items of the host graph. We pursue further this trend by proposing the Pullback-Pushout (pb-po) Approach, where we combine smoothly the classical modifications to a host graph specified by a rule (a span of graph morphisms) with the cloning of structures specified by another rule. The approach is shown to be a conservative extension of agree (and thus of the sqpo approach), and we show that it can be extended with standard techniques to attributed graphs. We discuss conditions to ensure a form of locality of transformations, and conditions to ensure that the attribution of transformed graphs is total