[topicmapmail] Question on Topic Map Ontologies

[rmorikaw@gmu.edu]

I have a question regarding ontology definition within topic maps=2E  Say=
 I have a topic map that addresses two or more ontologies that intersect=2E=
  By using the concept of topic map templates=2C I can create topic class=
es to define an ontology=2C and then add topic instances=2E  (i=2Ee=2E es=
sentially a topic map template per ontology=3F =96 does this make sense=3F=
)=2E

However=2C I=92m not sure how topic types are represented in the RM or th=
e HG4TM=2E

In the proposed hypergraph model=2C 12/3/2002 (Bernard Vatant=2C and orig=
inally from Pascal Auillans=2C et=2E al=2E) a triple is introduced consis=
ting of=3A

S =3D set of subjects
H =3D 5 tuple hypergraph
r =3D representation function

The hypergraph sets of vertices=2C edges=2C and incidences relate nicely =
to the S set subjects=2C assertions and role casting=3A

Association =3D r(edge)
Role casting =3D r(incidence)
Subject =3D r(vertex)

Within S=2C class typing is also provided for=3A

T(a=2C t)=2C  or assertion=2C a=2C  is of assertion type t
T(c=2C r)=2C or role casting=2C c=2C is of role type r

I did not see subject typing however=2C which I would=92ve guessed to be=3A=


T(s=2C sc)=2C or subject=2C s=2C is of subject class sc

I=92m probably missing something very fundamental here=2E  Does the absen=
ce of this last formula mean that a subject must be reified before it can=
 be an instance of a class=3F =2E=2Eand if so=2C how are topic class repr=
esented=3F

The RM is consistent with the HG4TM=2C so the same question arises =96 wh=
ere is the topic class-instance represented=3F  =


Thanks=2C Rik