CS 342 Lecture -*- Outline -*-

* The Blocks World example
	see pages 381ff
** How are Blocks represented?
	as functors (a b c)
** How are states represented?
	as lists of (on B Y) terms
	alternative representation see problem 7.b.
** different is needed because no negation
** What does clear do?  What kind of relation is it?
** What does update do?  What kind of relation is it?
** What does legal-move do?  What kind of relation is it?
** Transform
	look at simple code on 383ff
	see figure 8.14 for version using transform/4
			to keep track of visited states