[NOT ==== Syntax: [not <predication>] [NOT is a compound predication. It negates the truth value of the predication. All the variables that are used in the formula have to be bound before [NOT starts checking. In particular it should be made sure, that all the formulas, in which not is used, are internally converted into a simple predication, before not starts checking them. It is possible to negate composed formulas too if the internal conversion is taken into account. The rules of deMorgan are used for the conversion: not(A or B) == (not A) and (not B) not(A and B) == (not A) or (not B) [NOT returns the negated value and an unusable value. Example: >(ask [and [computer _x] [not [harddisk _x]]] (kb-format "~%~A" (name-of _x))) RAM CD-ROM NIL The interpreter searches for all components that are not a harddisk.