What ⥆ means
The surrounding notation decides its role.
The MathML 3 operator dictionary lists ⥆ as an infix operator, meaning it sits between the expressions it relates. That describes typesetting; a formula's author supplies the arrow's specific meaning.
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 2946, 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 arrow with plus below”.
Linux
Ctrl+Shift+UType 2946, then Enter or Space.
HTML
⥆CSS
\2946Codes and encoding1 code points
HTML decimal
⥆
HTML hex
⥆
CSS content
content: "\2946";
Each escape is closed by the next backslash; a trailing space is needed before a literal hex digit.
URL encoded
%E2%A5%86
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.