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Allegro CL

ANSI Common Lisp   12 Numbers   12.2 Dictionary of Numbers

 12.2.27 / Function

Syntax:
/ number    reciprocal

/ numerator &rest denominators+    quotient

Arguments and Values:
number, denominator - a non-zero number.

numerator, quotient, reciprocal - a number.

Description:
The function / performs division or reciprocation.

If no denominators are supplied, the function / returns the reciprocal of number.

If at least one denominator is supplied, the function / divides the numerator by all of the denominators and returns the resulting quotient.

If each argument is either an integer or a ratio, and the result is not an integer, then it is a ratio.

The function / performs necessary type conversions.

If any argument is a float then the rules of floating-point contagion apply; see Section 12.1.4 Floating-point Computations.

Examples:
``` (/ 12 4)  3
(/ 13 4)  13/4
(/ -8)  -1/8
(/ 3 4 5)  3/20
(/ 0.5)  2.0
(/ 20 5)  4
(/ 5 20)  1/4
(/ 60 -2 3 5.0)  -2.0
(/ 2 #c(2 2))  #C(1/2 -1/2)
```

Exceptional Situations:
The consequences are unspecified if any argument other than the first is zero. If there is only one argument, the consequences are unspecified if it is zero.

Might signal type-error if some argument is not a number. Might signal division-by-zero if division by zero is attempted. Might signal arithmetic-error.