# filename: ex203.rq

PREFIX dm: <http://learningsparql.com/ns/demo#> 
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>

CONSTRUCT
{
  ?s dm:problem dm:prob29 .
  dm:prob29 rdfs:label "Location value must be a URI." . 
}

WHERE
{
  ?s dm:location ?city .
  FILTER (!(isURI(?city)))
}