title: Shared Event Composition/Decomposition in Event-B
creator: Silva, Renato
creator: Butler, Michael
subject: Event-B
subject: Refinement
subject: Composition and reuse
subject: Model construction
subject: Rodin plug-ins
description: The construction of specifications is often a combination of smaller sub-components. Composition and decomposition are techniques that support reuse and allow us to formally combine sub-components through refinement steps while reusing their properties. Sub-components can result from a design or architectural goal and a refinement framework should allow further parallel development over the sub-components. We propose the definition of composition and decomposition in the Event-B formalism following a shared event approach where sub-components interact via synchronisation over shared events and shared states are not allow. We define the necessary proof obligations to ensure a valid composition or decomposition.  We also show that shared event composition preserves refinement proofs for sub-components, that is, in order to maintain refinement of compositions, it is sufficient to prove refinement between corresponding subcomponents.  A case study applying these two techniques is illustrated using Rodin, the Event-B toolset.
date: 2010-11
type: Conference or Workshop Item
type: PeerReviewed
format: application/pdf
identifier: http://deploy-eprints.ecs.soton.ac.uk/399/1/comp_decomp_paper.pdf
relation: http://www.informatik.uni-trier.de/~ley/db/conf/fmco/fmco2010.html
identifier:   Silva, Renato and Butler, Michael  (2010) Shared Event Composition/Decomposition in Event-B.  In: Formal Methods for Components and Objects 2010, November 2010, Graz, Austria.     
relation: http://deploy-eprints.ecs.soton.ac.uk/399/