Definition:Logical Not

Definition
The logical not or negation operator is a unary connective whose action is to reverse the truth value of the statement on which it operates.


 * $\neg p$ is defined as: $p$ is not true, or It is not the case that $p$ is true.

Thus the statement $\neg p$ is called the negation of $p$.

$\neg p$ is voiced not $p$.

In the statement $\neg p$, the scope of $\neg$ is $p$.

Truth Function
The logical not connective defines the truth function $f^\neg$ as follows:

Notational Variants
Various symbols are encountered that denote the concept of the logical not: