an Entity references as follows:
Scope note: This class comprises all persistent physical items that are purposely created by human activity. This class comprises man-made objects, such as a swords, and man-made features, such as rock art. No assumptions are made as to the extent of modification required to justify regarding an object as man-made. For example, a "cup and ring" carving on bedrock is regarded as instance of E24 Physical Man-Made Thing. Examples: - the Forth Railway Bridge (E22) - the Channel Tunnel (E25) - the Historical Collection of the Museum Benaki in Athens (E78) In First Order Logic: E24(x) ⊃ E18(x) E24(x) ⊃ E71(x)