How item semantics is accessed?
An item is represented by reference and in isolation it is semantically empty or primitive. In order to distinguish items semantically we need to get and compare their properties. However in the concept-oriented approach item properties are other items. Thus in order to compare items semantically we need to get other items, which also are characterized by other items and so on. This process can be continued until we get some primitive items with semantically interpretable references (normally numbers or text strings). In COM there exists two dual method for accessing item semantics: • getting a dimension value by following some upward arrow, or • getting an inverse dimension values by following some downward arrow All other operations in COQL are implemented by only using these two access methods normally applied to and producing collections. In other words, COQL provides convenient means for applying these two access methods to collections of items rather than to individual items. It
