Reeves, SteveStreader, David2008-03-192007-05-302008-03-192006-07-01Reeves, S., & Streader, D. (2006). Liberalising Event B without changing it. (Working paper series. University of Waikato, Department of Computer Science. No. 07/2006). Hamilton, New Zealand: University of Waikato.https://hdl.handle.net/10289/48We transfer a process algebraic notion of refinement to the B method by using the well-known bridge between the relational semantics underlying the B machines and the labelled transition system semantics of processes. Thus we define delta refinement on Event B systems. We then apply this new refinement to a problem from the literature that previously could only be solved by retrenchment.application/pdfenprocess refinementautomatic verificationframe refinementEvent BWorking Paper