decide how to model more complex OWL nestings

Docs show the classic SubClassOf SomeValuesFrom -> Edge pattern

E.g.

```
‘electron transport activity’ EquivalentTo 'oxidoreductase activity’ and ('part of' some 'electron transport chain')

<=>

ETA owl:eq _:1 .
_:1 a os:ClosedAnonClass .
_:1 rdfs:subClassOf OR .
<<_:1 part-of ETC>> os:interp op:AllSome .
```