The designs of TM Applications may be inherently more robust if all of the role types defined as components of their assertions types are regarded as unique subjects, even when they share the same names. For example, the father-daughter relationship type and the father-son relationship type may, in some cultures, be different in character, and the role of fatherhood may therefore also turn out to be different. If a TM Application defines both the father-daughter and father-son relationship types in such a way as to regard the role type of "father" as the same subject in both relationship types, then no distinction can ever be made between the two kinds of fatherhood, other than by defining a new TM Application.

Like the example but I am not sure here is the place for it.
Doubtful that its relationship to the prior paragraph could be made
clearer without a lot more room.