eqnarray

LaTeX2e help 1.6

### 2.6.5: eqnarray

       \begin{eqnarray}
       math formula 1 \\
       math formula 2 \\
       .
       .
       .
       \end{eqnarray}

The `eqnarray` environment is used to display a sequence of equations or inequalities. It is very much like a three-column `array` environment, with consecutive rows separated by `\\` and consecutive items within a row separated by an `&`.

An equation number is placed on every line unless that line has a `\nonumber` command.

The command `\lefteqn` is used for splitting long formulas across lines. It typesets its argument in display style flush left in a box of zero width.