By and large, I am quite happy with the LaTeX support provided by wordpress, which hosts my blog (and many other maths blogs out there); it is certainly superior to the maths support of most other off-the-shelf blog formats I have looked at. But it does have some annoying bugs and quirks; a lot of perfectly good LaTeX gets converted into “Formula does not parse”.

It occurred to me that maybe one should start a page that collects all the known bugs so that they can be sent at some point to the wordpress programmers to fix. So, here is my initial list of known bugs: any other wordpress users out there are very welcome to contribute their own.

Convention: I will drop the “latex” when I want to show a fragment of LaTeX source code without making it compile, e.g.

$\int_{-\infty}^\infty e^{-\pi x^2}\ dx = 1$ becomes \int_{-\infty}^\infty e^{-\pi x^2}\ dx = 1.

[Update, Feb 14: The bugs have now been fixed; see comments below.]

— The brackets bug —

This one comes up quite a lot: any LaTeX string that begins with a bracket [ automatically does not parse.  For instance,

$[a,b]$ becomes [a,b].

A workaround here is to put some filler in front of the bracket, e.g.

${}[a,b]$ becomes {}[a,b].

$\null [a,b]$ becomes \null [a,b].

— The trivial LaTeX bug —

When applying LaTeX to a single character, the parser sometimes gives up:

$ $ becomes $latex $.

$0$ becomes 0.

This can of course be worked around by using filler:

${} 0$ becomes {}0.

— The double spacing bug —

Most LaTeX strings that involve a double space seem to choke, e.g.

$x  y$ becomes x    y.

$a  f$ becomes a  f.

The workaround is, of course, not to use double spaces:

$x y$ becomes x y.

— The nested brackets bug —

If latex code contains brackets and is in turn contained in brackets, strange things can happen (and I don’t have a workaround for this, other than not to do it), in particular terminating the post prematurely:

$[[a,b]]$ becomes [[a,b]].

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