⊯
Negated Double Vertical Bar Double Right Turnstile
- Unicode
- U+22AF
- Category
- Math
- HTML Entity
- ⊯
- CSS
- \22AF
The ⊯ symbol, formally known as the Negated Double Vertical Bar Double Right Turnstile, is a mathematical operator used in formal logic. It acts as the negative counterpart to the double turnstile, indicating that a given set of premises does not logically entail a specific conclusion. While rarely seen outside advanced mathematics and computer science, it provides an essential shorthand for expressing semantic invalidity in formal proofs.
How to Type
- Windows
- In Word: type 22AF, then press Alt + X. Other apps have no standard Windows shortcut for it — copy it from this page
- macOS
- Control+Command+Space to open the Character Viewer, then search for 'turnstile'
- Linux
- Ctrl+Shift+U, type 22af, then press Enter
- HTML
- ⊯ or ⊯
In Programming
In mathematical typesetting and formal verification systems, ⊯ is used to demonstrate that a formula is not a semantic consequence of a model. It is most commonly rendered in LaTeX using the `\nVDash` command.
Tags
LaTeX negation
does not entail
formal logic
logic
mathematics
model
model theory
negated double vertical bar double turnstile
negation
negative of double turnstile
non-entailment
not satisfies
proof theory symbol
semantic invalidity
unicode U+22AF