Graph:
- opm:OPMGraph
- opm:Account

Nodes:
-opm:Artifact
-opm:Agent (*)
-opm:Process

Edges:
- opm:Time (*)
- opm:Role
- opm:Used, opm:UsedStar
- opm:WasControlledBy (*)
- opm:WasDerivedFrom, opm:WasDerivedFromStar,
- opm:WasGeneratedBy, opm:WasGeneratedByStar, 
- opm:WasTriggeredBy


Extensibility:
- opm:Annotation (*), opm:Property (*), 
    opm:Label, opm:PName, opm:Type, opm:Value, 
- opm:Profile (*)


(*) indicates terms that require refinement