Any two classes or two associations in any schema can be made equivalent semantically. Select the related Insert menu item, and ICOM will prompt you for two items in succession that will be declare equivalent, either in the same or in different schemas. Figure 10 shows the visual representacion of inter- and intra-schema equivalence axioms. Several context menu also contains options for creating equivalence axioms.
It is possible to add a class to an existing inter-schema equivalence axiom using the compose axiom button, or the associated Edit menu item. Equivalence axioms can be removed in the same way as classes and associations, with the function.