#round-trip_ticket__return_ticket  a ticket to a place and back (usually over the same route)
  supertype:  #ticket  a commercial document showing that the holder is entitled to something (as to ride on public transportation or to enter a public entertainment)
  subtype:  #day_return__dayreturn  a return ticket (at reduced fare) for traveling both ways in the same day

No statement uses or specializes #round-trip_ticket; click here to add one.