i am looking for a train to london liverpool street . i would like to leave friday and arrive by 17:45 .
there are many trains that travel from cambridge to london liverpool street . what day and time would you like to travel ?
{'service': 'train', 'act': 'inform', 'slot_name': 'day', 'value': 'friday'} {'service': 'train', 'act': 'inform', 'slot_name': 'leave', 'value': '17:59'} {'service': 'train', 'act': 'inform', 'slot_name': 'depart', 'value': 'cambridge'} {'service': 'train', 'act': 'inform', 'slot_name': 'dest', 'value': 'london liverpool street'} {'service': 'train', 'act': 'inform', 'slot_name': 'id', 'value': 'tr5212'} {'service': 'train', 'act': 'offerbook', 'slot_name': 'none', 'value': 'none'}
tr5212 departs from cambridge and arrives at london liverpool street . it leaves on friday 17:59 . would you like to book it ?