
List of Tables xxvii
Symbol Description
Sets and Spaces
R The set of all real numbers.
R
+
The set of positive real numbers.
Z The set of all integers.
N The set of all non-negative integers.
P The set of positive integers.
Q The set of rational numbers.
Z
N
{0, 1, 2, . . . , N − 1}
.
C The set of all complex numbers.
L
2
(R) The space of all square integrable
functions.
L
2
(Z) The space of all square integrable
functions over the integer grid.
[a, b] {x|x ∈ R and a ≤ x ≤ b}
(a, b] Left open, right closed interval, i.e.
{x|a < x and x ≤ b}.
u
(or u) u ( or u) is a point in Z
n
or R
n
and
also denoted as
u
= (u(1), u(2), . . . , u(n))
(or u
= (u
1
, u
2
, . . . , u
n
)).
|u
| Norm of