### A Technical Innovation

#### Posted by Tom Leinster

Here’s a new feature of the Café, thanks to our benevolent host Jacques Distler. If you ever want to see how someone has created some mathematical expression on this blog, there’s an easy way to do it.

With Firefox, you simply double-click on the expression. Try it: $A \times B^A \to B$ or $x_{m n}$ or $\Biggl( \begin{matrix} 1 & 2 \\ 3 & 4 \end{matrix} \Biggr).$ A window should pop up showing the TeX source.

With other browsers, I’m not so sure. Try double-clicking. If that doesn’t work, then, according to Jacques’s instructions, you “bring up the MathJax context-menu for the formula, and choose Show Math As $\to$ Annotation $\to$ TeX”. I don’t know how one brings up this menu. Does anyone else know? (**Update**: right-click in Chrome, Explorer and Opera, and control-click in Safari. Thanks to those who responded.)

Once you’ve made the TeX source appear, you can cut and paste to your heart’s content. Of course, most users here are fluent in LaTeX. But like most math-oriented websites, we use a variant of TeX that’s a little different from standard LaTeX, so this should turn out to be a helpful feature.

Posted at December 10, 2013 1:41 AM UTC
## Re: A Technical Innovation

In Chrome you can right-click with the mouse (or two-finger click on the touchpad) to bring up a context menu. Works here, shows the MathJax annotations no problem.