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Function 1+, 1-

Syntax

  • 1+ numbersuccessor
  • 1- numberpredecessor

Arguments and Values

Description

1+ returns a number that is one more than its argument number. 1- returns a number that is one less than its argument number.

Examples

(1+ 99)

100

(1- 100)

99

(1+ (complex 0.0))

#C(1.0 0.0)

(1- 5/3)

2/3

Affected By

None.

Exceptional Situations

Might signal type-error if its argument is not a number. Might signal arithmetic-error.

See Also

Notes

(1+ number) ≡ (+ number 1) (1- number) ≡ (- number 1)

Implementors are encouraged to make the performance of both the previous expressions be the same.