### Hypertext Help with LaTeX

# \lefteqn

`\lefteqn{eqn}`

prints `eqn` in display math style, but pretends that it has
zero width. It is typicaly used within an
`Eqnarray` environment for
displaying long equations that require multiple lines.
A typical use might be

`\begin{eqnarray}
\lefteqn{\int_0^\infty some expression =} \\
& & some terms \\
& & \mbox{} + more terms
\end{eqnarray}`

Note that the empty `\mbox{}` is so LaTeX
knows that the following `+` is a binary operator, and is not
attached to the first of the "more terms" as a unary operator.

Related topics
Return to LaTeX Table of Contents

Revised: Sheldon Green, 29 Jun 1995.