Grading Scheme for Quiz 4

Part I: Out of 5 points
        -1: Forgot to circle the tutorial.
        -3: Forgot either the name or the student number
        -5: If neither name or number on the quiz

Part II:

Accept any answer that proves IS is NP-complete, whether they use
CLIQUE or not.

3 points for proving IS is in NP
	3: anything convincing, possibly a minor error
	2: missed an important point or error
	1: at least knew they had to show IS in NP and tried, but wrong
	0: proof missing, or makes no sense

7 points for proving IS is NP-hard

    2 points for trying to apply a reasonable technique
	2: trying to reduce a NP-complete problem to IS
	1: trying to do a reduction, but backwards
	0: shows no understanding of proper techniques

    5 points for the proof
	5: the proof is generally correct
	4: has an important error or missing significant detail
		eg. not showing the reduction is polytime
	3: has several important errors or incomplete
		eg. simply describing the idea, the reduction does not
		seem polynomial, etc.
	2: incorrect proof, but shows understanding of reductions
		eg. tries to do a reduction, but ends up proving the reverse,
		the reduction is not polynomial, but a good try
	1: incorrect proof, and shows only superficial understanding
		or "I don't know how to prove it"
		eg. the reduction has no chance of being polynomial
	0: the proof is garbage, shows little understanding of reductions