Parses the prefix declaration of a namespace URI and returns the pair (prefix, namespace URI)
Parses the prefix declaration of a namespace URI and returns the pair (prefix, namespace URI)
Sth like Prefix(:=<http://purl.obolibrary.org/obo/pato.owl#>) or Prefix(dc:=<http://purl.org/dc/elements/1.1/>)
Trait to support the parsing of prefixes from expressions given in functional syntax.