n

F N n
$$f^{\prime}$$
 F

$$\begin{array}{r l r l}{F}&{{}}&{{}\{\ \}}\\ {F_{1}}&{{}}&{{}\{C-\{\ \}\ \ \ C\in F,\ \not\in C\}}\\ {}&{}&{{}}\\ {F_{1},n-}&{{}}&{{}}\\ {x}&{{}}&{{}}\\ {F_{1}}&{{}}&{{}\{C-\{\bar{x}\}\ \ \ C\in F,x\not\in C\}}\\ {F_{2}}&{{}}&{{}}\\ {F_{1},n-}&{{}}&{{}+{}}&{{}}\\ {\end{array}$$

 F

## 3. Average Running Time 3.1  The Recurrence Equation

m n F

$$C\qquad F$$

 F
p

$$\mathrm{ff}$$
$${\boldsymbol{F}}$$
f T m , n p  F F, n m  F m n mm F
Lemma 1  If F  contains m  clauses on n  variables, then there is a constant c  such that cmn bounds the time of executing one iteration of function CDP. W
O
 A
W
l l p k:
m s l F
461