Formal specification and practical verification of contextual component compatibility: technical report no. DCSE/TR-2011-06

In this report we formally describe and practically verify a method which ensures run-time type consistency of component-based applications, by performing type-based substitutability checks as part of the component binding and update processes. The method takes into account the environment of the currently deployed component version and uses its so-called contextual complement in the checks. This novel approach overcomes the limitations of the standard notion of compatibility by allowing non-contravariant di erences on the required side of the component's surface. The verification of the method uses an implementation for the OSGi component framework together with a simple GUI tool to perform component substitution experiments