# B.8 Display math should end with $$

You may have a dollar sign (`$`) in a displayed maths
environment, such as the `equation` environment.
Remember that `$`

is short hand for `\begin{math}`

or
`\end{math}`

, so you can't end one of the other environments
with a `$`

. (This error message is in fact a bit confusing,
as it seems to be suggesting that you end a displayed maths
environment with `$$`

which you also shouldn't do[Why use
`\[`...`\]` in place of $$...$$].)

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