# Tries to find out whether an appointment (02/10/2007 11:00-12:00) is possible

PREFIX  dc:   <http://purl.org/dc/elements/1.1/>
PREFIX  cal:  <http://www.example.org/Calendar#>
PREFIX  rdf:  <http://www.w3.org/1999/02/22-rdf-syntax-ns#>

ASK {
  ?x dc:title ?title.
  ?x cal:date ?y
  ?y cal:startDay ?start.
  ?y cal:endDay ?end.
  ?y cal:startTime ?sTime.
  ?y cal:endTime ?eTime
  FILTER (regex(?start,"2007-10-[0-9]{2}")).
  FILTER (!((?start = ?end && ?start = "2007-10-02" && ?sTime <"12:00" && ?eTime > "11:00" )||
          (?start != ?end && ?start = "2007-10-02" && ?sTime <"12:00")||
          (?start != ?end && ?end = "2007-10-02"  && ?eTime > "11:00" )||
          (?start < "2007-10-02" && ?end > "2007-10-02"))).
}