The Properties of Subject Reifiers are either "Built-in" or "Conferred"
- Properties can be "built into" reifiers:
- "Applications" can simply define certain subject reifiers as
being present in all the topic maps that instantiate any of their
properties.
- Authors of specific topic maps can also simply define
them as being present.
- "Built-in" properties are necessary. They allow a topic map
to be finite -- to have a perimeter beyond which its subjects
are not further explained by any statements about them.
- Gödel's Incompleteness Theorem is relevant.
