These proceedings record the papers presented at the 4th International Conf- ence of B and Z Users (ZB 2005), held in the city of Guildford in the south-east ofEngland. Thisconferencebuiltonthesuccessofthepreviousthreeconferences in this series, ZB 2000, held at the University of York in the UK, ZB 2002, held at theLaboratoire Logiciels Syst' emes R' eseaux within theInstitut d'Informatique et Math' ematique Appliqu' ees de Grenoble (LSR-IMAG) in Grenoble, France, and ? ZB 2003, held in Turku in Finland hosted by Abo Akademi University and the TurkuCentreforComputerScience(TUCS)....
These proceedings record the papers presented at the 4th International Conf- ence of B and Z Users (ZB 2005), held in the city of Guildford in the sou...