• R - the set of all real numbers
• R
+
- the set of all positive real numbers
• Z - the set of all integers
• N - the set of all positive integers
• Q - the set of all rationals
• (a, b) - open interval with the endpoints a and b
• [a, b] - closed interval with the endpoints a and b
• [x] - the integral part of a real number x
• For x e R,
sgnx =
( 1 for x 0,
- 1 for x 0,
0 for x = 0.
For n e N,
n! = 1 -2-3-...-n ,
(2n)!! = 2 • 4 • 6 •... • (2n - 2)(2n) and
(2n - 1)!! = 1 • 3 • 5 • ... • (2n - 3)(2n - 1).
If A c K is nonempty and bounded from above, then sup A
denotes the least upper bound of A. If a nonempty set A is
not bounded above, then we assume that sup A = -foo.
xin
