2.2.3 Negation
Negation is represented as follows:
- programming: not for languages that are not derived from C, ! for C-drived languages.
- engineering: the overbar is often used to denote negation. In other words,
means the negation of A. You can
also find text where a prime symbol means negation, the negation of A is, then, A′. Last, but not least, in some
text-only documents, the slash symbol as a prefix also means negation. In other words, the negation of A is /A
(this is mostly used in circuit diagrams and integrated circuit pinout descriptions).
- mathematics: the ¬ symbol is used to represent negation.
Negation, unlike conjunction and disjunction, is ¬⊆ 𝔹 × 𝔹. The individual members of this relation and function is as
follows:
- (true,false)
- (false,true)
Because negation only takes one parameter, it is not associative or commutative. However, it is a injective
and surjective function, with means it is bijective. The inverse function of negation is itself. This means that
∀A ∈ 𝔹 : ¬(¬(A)) = A.