The basic statement is a property relating two resources :
?person c:isMemberOf ?org
There can be several properties, related by an implicit logical AND :
?person c:isMemberOf ?org ?org c:name ?name
The query engine takes into account the associated RDF schema and infer resource types according to property signature.
For example if the RDF schema contains :
c:isMemberOf rdfs:range c:Organization
the ?org resource is typed
as c:Organization in the query. Type inference is not done in a negation (see below).