In summary: they invent a language to describe a form of graph rewriting and apply it to modify FBP graphs to introduce new "concerns" as overlayed subgraphs.

In summary: they invent a language to describe a form of graph rewriting and apply it to modify FBP graphs to introduce new "concerns" as overlayed subgraphs. The rewriting is limited to be performed in terms of a fixed set of patterns called "advices". There are two fundamental advices ("observer": branching an edge and "adapter": breaking an edge) and one special case ("collector": apply an observer to each top level node in a composite node). A Java implementation was developed.