Solve the water-jug puzzle given a 3-litter jug, named Three, and a 4-liter jug, named Four. Initially, Three and Four are empty. Either jug can be filled with water from a tap T, and one can discard water from either jug down a drain, D.
Water may be poured from one jug into the other. There is no additional measuring device.
Find a set of operations that will leave precisely two liters of water in Four. Hint: Leverage a state-space search formulation of the water-jug puzzle.
Name the operators on states and give precise descriptions of what each operator does to a state description.