src/swipl-devel/packages/xpce/man/refmanual/md/not.md

In rswipl: Embed 'SWI'-'Prolog'

class not {#class-not}

Class not defines negation of conditional statements. When executed, it executes its argument and fails if the argument is executed with success. See class code for more general information on executable objects.

@see class code @see class and @see class or @see topic Conditions

Instance variables {#class-not-instvars}

• not<->argument: code Conditional code object whose result is to be negated.

Send methods {#class-not-send}

• not->initialise: test=code Create from a single conditional test.

• not->_execute Execute the argument and succeed if and only if it fails.

rswipl documentation built on June 16, 2026, 5:07 p.m.