
Addition, Change of Sign, and Subtraction 17
1,3
so that
m--1
X -- ~ Xi ri
1.31
-f
7
For example, 0 < x < 7g is represented in radix-2 as
X-(X2 X1Xo.X-1X-2
X-3).
When representing fractions (no integer part), the convention used sometimes
is to assign positive indices to the fractional part. That is,
so that
X -- (X 1X2... X f)
1.32
f
x -- ~Xi r-i
1
1.33
Addition, Change of Sign, and Subtraction
In this section, we discuss addition, subtraction, change of sign, and overflow
detection.
1.3.1
Addition and Subtraction of Positive Integers
Consider the operation z = x +y in which the operands and the result are positive ...