are there trains arriving in cambridge before 18:45 on sunday ?
{'service': 'train', 'act': 'inform', 'slot_name': 'choice', 'value': 'many'} {'service': 'train', 'act': 'inform', 'slot_name': 'arrive', 'value': 'that time'}
there are many trains that arrive by that time . where will you be departing from ?