Artificial Intelligence

What are the steps of Problem solving? Assume you are given three empty jugs; a 3-gallon, a 5-gallon and a 9-gallon, and a pump can fill water only in 3-gallon jug. How you get exactly 7 gallons of water in the 9-gallon jug? Formalize the problems; write down production rules and draw search tree to solve this water Jug problem.