¬

Not Sign

Unicode
U+00AC
Category
Math
HTML Entity
¬
CSS
\00AC
The Not Sign (¬) is a mathematical symbol primarily used in logic to represent negation, effectively meaning "not" or flipping a statement's truth value from true to false. While essential in boolean algebra and computer science theory, internet users might recognize it from classic text-based emoticons (like the Lenny Face), where it serves as a flat or sideways-glancing eye.

How to Type

Windows
Alt+0172
macOS
Option+L
Linux
Compose + - + ,
HTML
¬ or ¬

In Programming

While modern programming languages typically use the exclamation mark (!) or tilde (~) for negation in actual source code, the ¬ symbol remains the gold standard in academic documentation, formal logic equations, and boolean algebra proofs.

Read full meaning article

Tags

bitwise not boolean boolean algebra computer science emoticon eye lenny face eye logic logical negation logical not mathematics negation not operator programming symbol tilde not

Related Symbols

± Plus Minus Sign × Multiplication Sign ÷ Division Sign ≠ Not Equal To ≈ Approximately Equal To ∞ Infinity √ Square Root ∑ Summation ∫ Integral π Pi ≤ Less Than or Equal To ≥ Greater Than or Equal To