Jori Dubrovin Tommi A. Junttila Keijo Heljanko Symbolic Step Encodings for Object Based Communicating State Machines. 96-112 2008 FMOODS http://dx.doi.org/10.1007/978-3-540-68863-1_7 conf/fmoods/2008 db/conf/fmoods/fmoods2008.html#DubrovinJH08