fname isa thing.
john isa fname.
mary isa fname.

lname isa thing.
smith isa lname.
clark isa lname.

age isa thing.
28 isa age.
35 isa age.

person isa thing.
* isa person.
* is john.
* is smith.
* is 35.

* isa person.
*'s fname is mary.
*'s lname is clark.
*'s age is 28.