joint declar convent jurisdict enforc judgment civil commerci matter brussel convent consolid version cf govern kingdom belgium feder republ germani french republ italian republ grand duchi luxembourg kingdom netherland sign convent jurisdict enforc judgment civil commerci matter desir ensur convent appli effect anxiou prevent differ interpret convent impair unifi effect recogn claim disclaim jurisdict aris applic convent declar readi studi question examin possibl confer jurisdict matter court justic european commun negoti agreement effect arrang meet regular interv repres wit whereof undersign plenipotentiari sign joint declar brussel twenti seventh dai septemb year thousand hundr sixti pierr harmel willi brandt michel debré giusepp medici pierr grégoir lun