@Article{BMPT:FI14,
   status = {public},
   number = {3-4},
   task = {T2.1},
   doi = {10.3233/FI-2014-1103},
   year = {2014},
   invited = {no},
   volume = {134},
   main = {no},
   issn = {0169-2968},
   title = {{On hierarchical graphs: reconciling bigraphs, gs-monoidal theories and gs-graphs}},
   author = {Roberto Bruni and Ugo Montanari and Gordon Plotkin and Daniele Terreni},
   period = {year4},
   journal = {Fundamenta Informaticae},
   abstract = {Compositional graph models for global computing systems
must account for two relevant dimensions, namely structural containment and communication linking.
In Milner's bigraphs the two dimensions are made explicit and
represented as two loosely coupled structures: the place
graph and the link graph. Here, bigraphs are
compared with an earlier model, gs-graphs, originally
conceived for modelling the syntactical
structure of agents with alpha-convertible declarations.
We show that gs-graphs are quite convenient also for the new purpose, since the two above mentioned dimensions can be recovered by considering
only a specific class of hyper-signatures.
With respect to bigraphs, gs-graphs can be proved
essentially equivalent, with minor differences at the interface level.
We argue that gs-graphs offer a simpler and more standard algebraic
structure, based on monoidal categories, for representing both states
and transitions. Moreover, they can be
equipped with a simple type system to check the well-formedness of legal
gs-graphs that are shown to characterise binding bigraphs.
Another advantage concerns a textual form in terms of
sets of assignments, which can make implementation easier in
rewriting frameworks like Maude.},
   partner = {UNIPI},
   wp = {WP2},
   pages = {287–-317}
}