1. A computer implemented method comprising the steps of: detecting a change to one or more conceptual paths, each path addressing a part of a structure of an ontology system, the ontology system being an application-independent representation of domain knowledge by a set of concepts and relationships between the concepts, the change being described by an ordered sequence of first operators defining semantic information on said change, the change comprising appending another structure to part of the ontology system structure, said another structure not being part of the ontology system structure before the change; defining one or more second operators that operate on a mapping from at least one application path of an intentional part of a data system to a conceptual path of the ontology system, the intentional part being prescribed by constraints on data elements and relationships between the data elements, each application path addressing a part of the structure of the data system, said one or more second operators being equivalent to said one or more first operators used to describe said change to said one or more conceptual paths addressing said part of the structure of said ontology system; and updating said mapping with said one or more equivalent second operators to reflect the change to said one or more conceptual paths addressing said part of the structure of the ontology system.