3. The system of claim 1 wherein the correspondence test is configured to compare an identifier of the element with an identifier of a subclass of the class of the further entity group.
3. The system of claim 1 wherein the correspondence test is configured to compare an identifier of the element with an identifier of a subclass of the class of the further entity group. 4. The system of claim 3 wherein the correspondence test is configured to test if any one of the following relations exists between identifiers of the element and the subclass: the identifiers are identical, the identifiers are synonymous, the identifiers are similar according to a first similarity test.