What ↞ means
It is a left-pointing, two-headed arrow in mathematical notation.
In AMS LaTeX, the amssymb package provides it as \twoheadleftarrow. That is a mathematical typesetting command; the surrounding formula or diagram supplies the specific relation.
Don't confuse it with
4Questions people ask
1Does ↞ flip in right-to-left text?
No. A 2018 Unicode proposal on bidirectional math says mathematical arrows are not automatically mirrored in right-to-left text, so choose the arrow that states the intended direction.
How to type ↞
Windows (Word)
Alt+XType 219E, 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 “leftwards two headed arrow”.
Linux
Ctrl+Shift+UType 219e, then Enter or Space.
HTML
↞CSS
\219EHow to type ↞
In LaTeX, load the `amssymb` package and use `\twoheadleftarrow`.
Codes and encoding1 code points
HTML decimal
↞
HTML hex
↞
CSS content
content: "\219E";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%86%9E
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.