A (10). Create a global variable *start-state* whose value represents the initial state
B (20). Create a global variable *tower-ops* to store the name of each operator
C (20). Define Lisp functions for each operator. An operator takes a state as an argument and returns NIL or a new state. It doesn't modify its argument.
D (20). Define a function solution-state? that determines whether a state is the solution state. You want to use the definition of sorted? from Homework 1
E (5). By hand, find some way of combining the operators so that the state is transformed to a goal state. For example, in the jug problem, one solution is:
(fill-three-from-four (fill-four (empty-four-into-three (dump-three (fill-three-from-four (fill-four *start-state*)))))) #S(JUG-CONTENTS :FOUR 2 :THREE 3) (solution-state? (fill-three-from-four (fill-four (empty-four-into-three (dump-three (fill-three-from-four (fill-four *start-state*) )))))) T
2. (10 points) Solve your Towers of Hanoi problem (above) with breadth first search. You can load the code for breadth first search in the file blind-search.lisp. Make sure you compile blind-search.lisp if you are running on a sun. It might be easier to debug if you start with a simpler problem first, such as moving 1 disk from A to C. Once you can do that without errors, try 2 disks, and then finally 3.
Turn in a single file, which is a listing of your program, and a dribble file showing it working for 1.E (as above) and 2.