Left Vector in LaTeX (\overleftarrow{AB})

Where it is used

Draws a left-pointing arrow spanning the argument, marking reversed direction or a backward-read sequence.

Less common than its right-pointing counterpart, \overleftarrow{AB} appears when a vector or path is read from B back to A, for the reversed word or string in formal language theory, and for backward-time or adjoint quantities in physics. Its arrow stretches across the full argument just like \overrightarrow. If you need arrows under the expression instead, amsmath supplies \underleftarrow and \underrightarrow. For a single-letter backward vector there is no built-in short form like \vec, so this wide command is the usual choice.

Minimal compilable example

Paste this into an empty .tex file and compile it with pdfLaTeX, XeLaTeX or LuaLaTeX.

\documentclass{article}
\begin{document}
Left Vector: $\overleftarrow{AB}$

\[ \overleftarrow{w} = a_n a_{n-1} \cdots a_1 \]
\end{document}

Related symbols

• Line Arrow (over AB)\overleftrightarrow{AB}
• Wide Vector\overrightarrow{AB}
• Acute\acute{x}
• Vector Arrow\vec{x}
• Grave\grave{x}
• Underline\underline{xyz}

Frequently asked questions

How do I write Left Vector in LaTeX?

Type \overleftarrow{AB} in math mode, for example $\overleftarrow{w} = a_n a_{n-1} \cdots a_1$. It works in plain LaTeX without loading any package.

Which package do I need for \overleftarrow{AB}?

None. \overleftarrow{AB} is part of standard LaTeX, so it compiles with nothing in the preamble but the document class.

Can I use \overleftarrow{AB} in text mode, or only in math mode?

Both. \overleftarrow{AB} compiles in running text as well as inside $...$; in a formula keep it in math mode so it gets math fonts and spacing.