Higraphs, a kind of hierarchical graph, underlie a number of sophisticated diagrammatic formalisms, including Statecharts. Naturally arising from hierarchy in higraphs is an abstraction operation known as zooming out, which is of profound importance to reasoning about higraph-based systems. We motivate how, in general, the use of zooming in reasoning requires sophisticated extensions to the basic notion of higraph and a careful definition of higraph dynamics (i.e. semantics), which we contribute. Our main results characterise zooming by means of a universal property and establish a precise relationship between the dynamics of a higraph and that of its zoom-out.
|Title of host publication||Foundations of Software Science and Computation Structures 6th International Conference, FOSSACS 2003 Held as Part of the Joint European Conferences on Theory and Practice of Software, ETAPS 2003 Warsaw, Poland, April 7–11, 2003 Proceedings|
|Place of Publication||Berlin|
|Number of pages||17|
|Publication status||Published - 2003|
|Name||Lecture Notes in Comput. Sci.|