book me a train from bishops stortford that arrives by 18:30 .
user
ok , the tr0201 arrives at 18:07 . would you like to book that ?
assistant
i need the train to leave on tuesday and go to cambridge .
user
there are no trains on tuesday .
assistant
are you sure ? i need to leave tuesday .
user
yes i am sure . can you change your criteria ?
assistant
no , i can not do that .
user
i have a train on tuesday that arrives at 18:07 . i believe that would suffice ?
assistant
can you book it for me and get a reference number ?