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	ub
	lb
defn of decision tree
	cost(T,x)
	depth
defn of D(f)
	\le n
D(or)
defn of N_1(f), N_0(f)
	analogues of NP, coNP
lem: N_b(f)\le D(f)
lem: N_0(OR)=n
lem: N_1(OR)=1
prop: D(f)\le N_0(f)\cdot N_1(f)
pf
defn
	R_0(f)=min_{prob dist} max_{input} \E[cost]
rmk:
	zero error
	ZPP
Q. P vs ZPP (vs BPP)?
ex: R_0(MAJ_3)=8/3
lem: R_0(f)\ge N_b(f)
cor: D(f)\le R_0(f)^2
Q. ZPP vs NP?
prop: R_O(OR)\ge \Omega(n)
thm: 	zero sum game
	von Neumann minimax
pf:
	LP duality
prop: R_O(OR)\ge \Omega(n)