# Double backslashes no longer working in TeX

I was pretty sure the admins had fixed things so that two backslashes worked to insert a new line in TeX, but it no longer seems to work. Or rather, it works in the preview page, but not in the final output.

Two backslashes: \begin{bmatrix}a&b\\c&d\end{bmatrix} produces $$\begin{bmatrix}a&b\\c&d\end{bmatrix}$$

Three backslashes: \begin{bmatrix}a&b\\\c&d\end{bmatrix} produces $$\begin{bmatrix}a&b\\\c&d\end{bmatrix}$$

Click "edit" to see the desired behaviour.

• It seems that some commands no longer do the right escapes; the triple-backslash has always been necessary in align environments, so far as I can tell, and seems to be required every so often; lately, I've been seeing a disconnect again between the previewer and the renderer on \{ and \} on in-line equations as well. – Arturo Magidin Jan 24 '11 at 20:46
• @Arturo: Here is an answer I wrote recently using double backslashes in an align environment. Strangely enough, it still works. – Rahul Jan 24 '11 at 20:52
• Don't know; I keep using double backslash in align*s. Maybe it's the stars. – Arturo Magidin Jan 24 '11 at 20:56