The API documentation describes subjects as "Subjects are representations of a subject".
This is terminologically incorrect; subject are subjects, not representations; i.e., http://example.org/subjects/Mathematics identifies the concept of maths, not a representation of the concept.
A correct (and less tautological) way to describe things would be "A subject is a branch of knowledge studied or taught in an educational institution". Similar for other properties.
The API documentation describes subjects as "Subjects are representations of a subject". This is terminologically incorrect; subject are subjects, not representations; i.e., http://example.org/subjects/Mathematics identifies the concept of maths, not a representation of the concept.
A correct (and less tautological) way to describe things would be "A subject is a branch of knowledge studied or taught in an educational institution". Similar for other properties.