This query does the trick:

select o.prop_id, l.starttime, e.revno, e.sch_dur, o.srcname, f_ra_hrs(o.ra), f_dec_hrs(o.dec) from exposure e, eventlist l, obs o where
e.revno >= ? and
e.revno <= ? and
e.prop_id = ? and 
e.posversion = f_latestpos(e.revno) and
l.eventlistno = e.eventlistno and
l.eventno = e.eventno and
l.revno = e.revno and
l.posversion = e.posversion and
e.prop_id = o.prop_id and
e.obsno = o.obsno;