Maybe not exactly what you are looking for, but it could help you..
If you download the Model Reflection Modulefrom the marketplace, you will be be able to convert your model into readable data. If you look at the screenshot of the domain model below, you can see that the MXObjectReference entity contains the information about the ReferenceType (Reference, Reference Set) and Association Owner (Default, Both) which will allow you to tell what the association between entities (associated objects in MxObjectType) are exactly.