How do I represent this relation in OWL?

Hi,
I have the concepts 'Role' and 'File' connected by the object property
'hasPersmission'. ie. A Role hasPermission to a File. I would like the
'hasPermission' property to also contain the type of permission like
read,write etc.
I will eventually have SWRL rules to
1.list all the permissions a specific role has on a file and
2.find out if a role has a specific permission on a file

I would like to know how to model this relationship using OWL so that my
rules could be formulated accordingly.

Thanks.