What ⤌ means
Read the symbol from the surrounding formula. Unicode's general arrow guidance says an arrow's meaning can vary by application. Here, the formula has to identify the relation; the glyph alone cannot do that.
It belongs to a dash-arrow series: ⤍ points right with two dashes, while ⤎ and ⤏ point left and right with three. Their matching shapes connect the forms, but do not give them a universal reading.
How does ⤌ behave in MathML?
MathML treats it as a stretchy infix operator and an accent. An infix operator sits between parts of an expression; stretchy means layout software may lengthen the arrow to fit. The accent property lets MathML use it as a mark attached to a mathematical expression.
The unicode-math package supplies the LaTeX command \leftbkarrow. It produces the character; the notation around it supplies the intended meaning.
A specialist mathematical symbol that can look like an unexplained arrow in ordinary prose.
The arrow's direction alone does not tell you what relation the formula intends.
Don't confuse it with
4Questions people ask
1Is ⤌ an emoji?
No. It is a text symbol used in mathematical notation; its reading depends on the expression around it.
How to type ⤌
⤌\290CCodes and encoding1 code points
A visible symbol can contain several code points. JS .length counts UTF-16 units; UTF-8 counts bytes.