Grit Denker Jonathan K. Millen Modeling Group Communication Protocols Using Multiset Term Rewriting. 2002 71 Electr. Notes Theor. Comput. Sci. http://www1.elsevier.com/gej-ng/31/29/23/145/23/show/Products/notes/index.htt#003 db/journals/entcs/entcs71.html#DenkerM02