
ANSI Common Lisp 12 Numbers 12.2 Dictionary of Numbers
12.2.1 number 
System Class 
 Class Precedence List:

number,
t
 Description:

The type number contains objects which represent
mathematical numbers.
The types real and complex are disjoint
subtypes of number.
The function = tests for numerical equality.
The function eql, when its arguments are both numbers,
tests that they have both the same type and numerical value.
Two numbers that are the same under eql or =
are not necessarily the same under eq.
 Notes:

Common Lisp differs from mathematics on some naming issues. In mathematics,
the set of real numbers is traditionally described as a subset of the
complex numbers, but in Common Lisp, the type real and the type complex are
disjoint. The Common Lisp type which includes all mathematical complex
numbers is called number. The reasons for these differences
include historical precedent, compatibility with most other popular
computer languages, and various issues of time and space efficiency.
 Allegro CL Implementation Details:

None.
