Charles Lakos tries to show in one of his papers the natural evolution
from CPNs to OPNs. The Paper is called "From Coloured Petri Nets to
Object Petri Nets".

@incollection{ lakos95from,
    author = "C. A. Lakos",
    title = "From Coloured {P}etri Nets to Object {P}etri Nets",
    booktitle = "Proceedings of the Application and Theory of Petri Nets 
1995",
    volume = "935",
    publisher = "Springer-Verlag",
    address = "Berlin, Germany",
    pages = "278--297",
    year = "1995",
    url = "citeseer.nj.nec.com/lakos95from.html" }

In this paper he introduces a different CPN formalism than Jensen in which
multiple arcs are not allowed, melting them to a single arc that is 
inscripted with an expression of a multiset-type. Therefore places have
multiset-types.

However he does not change the definition of a token element regarding the
contained tokens: (p,c) where p in P and c in C. Using his definition
the "get" function cannot be evaluated for for an arc inscription like
2`a since it would evaluate to something like 2`(p,2`1) if a were bound
to 1 but "get" should evaluate to a multiset of token elements. Changing 
the token element definition to c in C* would leave the problem of the 
definition of a marking...

Does anybody work here with Lakos OPNs to help me with that issue?
Thanks in advance,
Stephan