[Activerdf] Inherited predicates

[Joost Ouwerkerk]

I have an ontology wherein a City is an <rdfs:subClassOf> Place, and has
a property 'hasName'.  So City inherits this property.

ActiveRDF doesn't seem to recognize this as a valid predicate: 
        ActiveRdfError Exception: could not set hasName to Test: no
        suitable    predicate found. Maybe you are missing some schema
        information?

I am new to ActiveRDF, and still trying to figure things out.  What
should I be doing to be able to set inherited properties?