Simplified Common Lisp reference

Symbol class: Mathematics, Arithmetics, Logic and Comparisons

Syntax:

Symbol type: function

1-number => number

Argument description:

number

numeric value

1- function subtracts one from the argument. See -.

(1- 5) => 4
(1- 1234567890123456789) => 1234567890123456788
(1- 1.3) => 0.29999995
(1- 1.3d0) => 0.30000000000000004d0
(1- #c(2 4)) => #C(1 4)
(1- 3/4) => -1/4

Function index Full documentation for 1- (HyperSpec)