PREFIX ex: <https://example.com/>
PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>

ex:FoafProfile EXTRA a {
  a [ foaf:Person ]
    // rdfs:comment  "Defines the node as a Person (from foaf)" ;
  foaf:name xsd:string ?
    // rdfs:comment  "Define a person's name." ;
  foaf:img xsd:string ?
    // rdfs:comment  "Photo link but in string form" ;
  foaf:knows @ex:FoafProfile *
    // rdfs:comment  "A list of WebIds for all the people this user knows." ;
}