Prolog Expert

Hi I am looking Proglog Expert. I wrote some code on prolog. I have to make something else on it. Details; I have some travelling information such as; timetable( edinburgh, london, [ 9:40 / 10:50 / ba4733 / alldays, 13:40 / 14:50 / ba4773 / alldays, 19:40 / 20:50 / ba4833 / [mo,tu,we,th,fr,su] ] ). timetable( london, edinburgh, [ 9:40 / 10:50 / ba4732 / alldays, 11:40 / 12:50 / ba4752 / alldays, 18:40 / 19:50 / ba4822 / [mo,tu,we,th,fr] ] ). timetable( london, ljubljana, [ 13:20 / 16:20 / jp212 / [mo,tu,we,fr,su], 16:30 / 19:30 / ba473 / [mo,we,th,sa] ] ). I can get result from my code; Problem is to find minimzed time, or minimize transfer etc.. For example if you enter edinburgh ljubljana. (from,To) You have to go; first london then london to ljubljana. So i want to find minimum waiting time between them Time should be selected as 09:40 10:50 for edinburg to london then 13:20 to 16:20 for london to ljubljana. I am looking someone to do it. I can take at most 30 min i think. Thanks