The Real Numbers
In this text we use the set of real numbers as the universal set. We can represent the real
numbers along a line called the real number line. This number line is a picture, or graph,
of the real numbers. Each point on the real number line corresponds to exactly one real
number, and each real number can be located at exactly one point on the real number line.
Thus, two real numbers are said to be equal whenever they are represented by the same
point on the real number line. The equation a 5 b (a equals b) means that the symbols a
and b represent the same real number. Thus, 3 + 4 = 7 means that 3 + 4 and 7 represent
the same number. Table 0.1 lists special subsets of the real numbers