Oct 6, 2003
-------------

- Other approaches to reasoning
	- forward chaining, e.g., CLIPS
	- backward chaining, e.g., PROLOG

- Recap forward chaining
	- good when KB consists of horn clauses

- Tricks to forward chaining
	- index predicates and facts
	- order the checks
	- magic rewriting
	- careful book-keeping

- Backward chaining
	- start with the goal
	- replace with new conjuncts to be satisfied
	- attempt to prove (recurse)

- Example of a backward chaining system 
	- PROLOG
	- different ways of defining ancestors
	- left recursion and bad ordering will cause
	  infinite loops

- Done with knowledge representation!
	- onto next topic