DAML JBI TIE - slide "Limitations of Class Expressions"

see Venn Diagram: Expressive Overlaps among KR's (page 6)
DQL covers DL and Horn Logic Programs because it's a rule language that also uses OWL types

an example of a DQL query that can't be expressed as a DL class expression: domestic flights

?flight rdf:type flight:Flight
?flight flight:origin ?origin
?flight flight:destination ?dest
?origin airport:country ?country
?dest airport:country ?country

probably not a requirement to support such queries (at least initially)