i need a train to leave from cambridge after 15:30 .
{'service': 'train', 'act': 'request', 'slot_name': 'dest', 'value': '?'} {'service': 'train', 'act': 'request', 'slot_name': 'day', 'value': '?'}
ok , lets get you set up , where are you going and on what day ?