Every-single-thing indicates all individuals in the open-world assumption. Individuals may be already defined in the ontology or not defined but possibly existing. It is often used for writing axioms about roles.


Those examples show how to use every-single-thing declaration to indicate all existing individuals and specify more information about them. Combined with that keyword, it can be used for writing more complex rules.

Example: All the individuals in the world are specified with the role 'is-married-to' something.
Every-single-thing is-married-to something.
Example: If something has a wife, then it must be a person. Range of is-a-wife-of property is a person class
Every-single-thing is-a-wife-of nothing-but persons.
Example: Being someone's wife indicates being a woman. Domain of is-a-wife-of property is a woman class.
Every-single-thing that is-a-wife-of is a woman.
Example: Only people have names. If something has a data property value called name, then it is a person.
Every-single-thing that has-name (some value) is a person.
Example: Axiom on a role. 'to be part of' is reflexive.
Every-single-thing is-part-of itself.