2-Term Charters.
Alexander Knapp, Marı́a Victoria Cengarle · The Journal of Object Technology · 2020
Building on Martin Gogolla's algebraic formalisation of the "Object Constraint Language" (OCL), its expression part has been formalised as a syntactically and semantically heterogeneous language using the framework of term charters for faithfully integrating OCL's features in a step-wise and compositional manner.This schema for the evaluation of OCL expressions on a single system state is now extended to comprise OCL contracts, i.e., the specification of operations with pre-and post-conditions.Under mild assumptions term charters can be systematically transformed into 2-term charters involving two system states.The application to OCL as a heterogeneous expression and contract language is illustrated by several examples.