Introduction to
Logic Programming
What
versus
How
 

Exercise 11.6 - Travel


Amy, Bob, Coe, and Dan are traveling to different places. One goes by train, one by car, one by plane, and one by ship. Amy hates flying. Bob rented a jeep. Coe tends to get seasick. And Dan loves trains. Assume we have symbols amy, bob, coe, and dan for the travelers, symbols car, plane, ship, and train for modes of transportation, symbols v, x, and e for "truth values", and a ternary relation t that relates a traveller, a mode of transportation, and a truth value. Write update rules to solve this problem by constraint propagation.