What ∳ means
The circle closes the contour; the arrow points anticlockwise. A contour is the integration path; a closed one returns to its start.
Cauchy’s contour-integral work developed in the 19th century. Wilson used circle-marked closed-path notation in 1901; an early circle-in-integral example by Sommerfeld followed in 1917.
Don't confuse it with
1Questions people ask
1Can right-to-left text flip the arrow?
No. Unicode’s bidirectional layout rules keep the clockwise and anticlockwise marks pointing as encoded.
How to type ∳
Windows (Word)
Alt+XType 2233, 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 “anticlockwise contour integral”.
Linux
Ctrl+Shift+UType 2233, then Enter or Space.
HTML
∳CSS
\2233Word
In Word’s linear UnicodeMath equation input, type `\aoint`.
LaTeX
Use `\ointctrclockwise` with a package that defines directional contour integrals.
Codes and encoding1 code points
HTML decimal
∳
HTML hex
∳
CSS content
content: "\2233";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%88%B3
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.