Miquel Bertran Francesc-Xavier Babot August Climent An Input/Output Semantics for Distributed Program Equivalence Reasoning. 25-46 2005 137 Electr. Notes Theor. Comput. Sci. 1 http://dx.doi.org/10.1016/j.entcs.2005.01.038 db/journals/entcs/entcs137.html#BertranBC05