inform((_:search,day,'friday');(_:search,departure,'london liverpool street');(_:search,type,'Train'))
user
I need a train leaving from london liverpool street on friday .
inform((_:booking,category,'Train');(_:booking,ref,'H58I0WC3');(_:booking,ticket,'16.6 GBP payable at the station');(_:booking,type,'Booking'))
system
Booking was successful , the total fee is 16.6 GBP payable at the station . 
 Reference number is : H58I0WC3 .
request((_:result,day,?);(_:result,leave_at,?);(_:result,type,'Train'))
user
Please review your trip itinerary
inform((_:result,arrive_by,'07:07');(_:result,day,'friday');(_:result,departure,'Liverpool Street');(_:result,destination,'Cambridge');(_:result,leave_at,'05:39');(_:result,type,'Train')) reqmore()
system
The train departs Liverpool Street on friday at 05:39 and arrives in Cambridge at 07:07 . Is there anything else I can assist you with ?
request((_:result,duration,?);(_:result,type,'Train'))
user
How long is the travel time for that train ?
inform((_:result,duration,'88 minutes');(_:result,type,'Train'))
system
88 minutes to travel
bye()
user
Thanks , that will be all . Good bye .
system
Goodbye now ! Have a great day !
_:search day friday
_:search departure london liverpool street
_:search type Train
_:search day friday
_:search departure london liverpool street
_:search type Train
_:booking category Train
_:booking ref H58I0WC3
_:booking ticket 16.6 GBP payable at the station
_:booking type Booking
_:result day ?
_:result leave_at ?
_:result type Train
_:search day friday
_:search departure london liverpool street
_:search type Train
_:booking category Train
_:booking ref H58I0WC3
_:booking ticket 16.6 GBP payable at the station
_:booking type Booking
_:result arrive_by 07:07
_:result day friday
_:result departure Liverpool Street
_:result destination Cambridge
_:result leave_at 05:39
_:result type Train
_:system inquired _:user
_:result duration ?
_:search day friday
_:search departure london liverpool street
_:search type Train
_:booking category Train
_:booking ref H58I0WC3
_:booking ticket 16.6 GBP payable at the station
_:booking type Booking
_:result arrive_by 07:07
_:result day friday
_:result departure Liverpool Street
_:result destination Cambridge
_:result leave_at 05:39
_:system inquired _:user
_:result duration 88 minutes
_:result type Train
_:user dismissed _:system