What ⊡ means
No. A definition in one paper need not carry to another.
In algebra, a paper may define ⊡ as a binary operation—a rule that combines two inputs. In modal logic, which studies necessity and possibility, some authors use it for noncontingency: whether a statement is necessarily true or necessarily false.
Don't confuse it with
4Questions people ask
1Why does ⊡ show as a box on some devices?
Because that device's fonts have no glyph for it. The character is still correct and still copies correctly — the box is a missing glyph, not a broken character.
How to type ⊡
Windows (Word)
Alt+XType 22A1, then Alt+X to get ⊡.
Windows
Win+Rrun charmap for the full table, or use the emoji picker's Ω symbols tab (Win + .).
macOS
Control+Command+SpaceOpen the character viewer and search “squared dot operator”.
Linux
Ctrl+Shift+UType 22a1, then Enter or Space.
HTML
⊡CSS
\22A1LaTeX or KaTeX
To type boxdot in LaTeX, load the `amssymb` symbol package before `\begin{document}` and write `\boxdot` in math mode. KaTeX supports it as of October 2026.
Microsoft Word
To type boxdot in Word, enter `\boxdot` and press Space or Enter. Word documents it as an equation AutoCorrect command as of October 2026.
Codes and encoding1 code points
HTML decimal
⊡
HTML hex
⊡
CSS content
content: "\22A1";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%8A%A1
1
On screen
1
Code points
1
JS .length
3
UTF-8 bytes
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.