Next: , Previous: bignum, Up: Numbers


=, /=, <, >, <=, >= (Function)

Syntax:
— Function: = &rest numbers+ generalized-boolean
— Function: /= &rest numbers+ generalized-boolean
— Function: < &rest numbers+ generalized-boolean
— Function: > &rest numbers+ generalized-boolean
— Function: <= &rest numbers+ generalized-boolean
— Function: >= &rest numbers+ generalized-boolean
Arguments and Values:

number—for <, >, <=, >=: a real; for =, /=: a number.

generalized-boolean—a generalized boolean.

Description:

=, /=, <, >, <=, and >= perform arithmetic comparisons on their arguments as follows:

=

The value of = is true if all numbers are the same in value; otherwise it is false. Two complexes are considered equal by = if their real and imaginary parts are equal according to =.

/=

The value of /= is true if no two numbers are the same in value; otherwise it is false.

<

The value of < is true if the numbers are in monotonically increasing order; otherwise it is false.

>

The value of > is true if the numbers are in monotonically decreasing order; otherwise it is false.

<=

The value of <= is true if the numbers are in monotonically nondecreasing order; otherwise it is false.

>=

The value of >= is true if the numbers are in monotonically nonincreasing order; otherwise it is false.

=, /=, <, >, <=, and >= perform necessary type conversions.

Examples:

The uses of these functions are illustrated in the next figure.

(= 3 3) is true. (/= 3 3) is false.
(= 3 5) is false. (/= 3 5) is true.
(= 3 3 3 3) is true. (/= 3 3 3 3) is false.
(= 3 3 5 3) is false. (/= 3 3 5 3) is false.
(= 3 6 5 2) is false. (/= 3 6 5 2) is true.
(= 3 2 3) is false. (/= 3 2 3) is false.
(< 3 5) is true. (<= 3 5) is true.
(< 3 -5) is false. (<= 3 -5) is false.
(< 3 3) is false. (<= 3 3) is true.
(< 0 3 4 6 7) is true. (<= 0 3 4 6 7) is true.
(< 0 3 4 4 6) is false. (<= 0 3 4 4 6) is true.
(> 4 3) is true. (>= 4 3) is true.
(> 4 3 2 1 0) is true. (>= 4 3 2 1 0) is true.
(> 4 3 3 2 0) is false. (>= 4 3 3 2 0) is true.
(> 4 3 1 2 0) is false. (>= 4 3 1 2 0) is false.
(= 3) is true. (/= 3) is true.
(< 3) is true. (<= 3) is true.
(= 3.0 #c(3.0 0.0)) is true. (/= 3.0 #c(3.0 1.0)) is true.
(= 3 3.0) is true. (= 3.0s0 3.0d0) is true.
(= 0.0 -0.0) is true. (= 5/2 2.5) is true.
(> 0.0 -0.0) is false. (= 0 -0.0) is true.

Figure 12.13: Uses of /=, =, <, >, <=, and >=

Exceptional Situations:

Might signal type-error if some argument is not a real. Might signal arithmetic-error if otherwise unable to fulfill its contract.

Notes:

= differs from eql in that (= 0.0 -0.0) is always true, because = compares the mathematical values of its operands, whereas eql compares the representational values, so to speak.