# Definition:Logical Not/Notational Variants

## Definition

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

Symbol Origin Known as
$\neg p$
$\mathsf{NOT}\ p$
$\sim p$ or $\tilde p$ 1910: Alfred North Whitehead and Bertrand Russell: Principia Mathematica tilde or curl
$- p$
$\bar p$ Bar $p$
$p'$ $p$ prime or $p$ complement
$! p$ Bang $p$
$\operatorname{N} p$ Łukasiewicz's Polish notation