> When an owl:inverseOf production rule is defined, the inverse property triple is inferred by the reasoner either when adding or updating the store, or when selecting from the store. This is a "materialized relation"
> Schema.org - an RDFS vocabulary - defines, for example, https://schema.org/isPartOf as the inverse property of hasPart. If both are specified, it's not necessary to run another graph pattern query to traverse a directed relation in the other direction. (:book1 schema:hasPart ?o), (?o schema:isPartOf :book1), (?s schema:hasPart :chapter2)
> It's certainly possible to use RDFS and OWL to describe schema for and within neo4j property graphs; but there's no reasoner to e.g. infer inverse properties or do schema validation.
> Is there any RDF graph that neo4j cannot store? RDF has datatypes and languages for objects: you'd need to reify properties where datatypes and/or languages are specified (and you'd be re-implementing well-defined semantics)
> Can every neo4j graph be represented with RDF? Yes.
> RDF is a representation for graphs for which there are very many store implementations that are optimized for various use cases like insert and query performance.
> Comparing neo4j to a particular triplestore (with reasoning support) might be a more useful comparison given that all neo4j graphs can be expressed as RDF.
How do you see property graphs as distinct from RDF?
People build terrible apps without schema or validation and leave others to clean that up.