Gullstrand-Painleve/Doran articles with bad Latex?

[m4r35n357]

I've been intrigued for some time by the following posts, but they all have lots of Latex errors (at least for me, Firefox/Linux).
https://www.physicsforums.com/blog.php?b=580
https://www.physicsforums.com/blog.php?b=590
https://www.physicsforums.com/blog.php?b=855
Can anyone confirm they are broken before I make an idiot of myself in a PM, and in any case is it appropriate to PM for this sort of thing?

 

[Mentz114]

I see a lot of broken Latex with FireFox

$$\begin{flalign} dt\,+\,\frac{\beta}{1-\beta^2}\,dr&=&d\bar{t}&=& &d\breve{t}-\,\frac{1}{1+\beta}\,dr\\[6mm] d\phi\,+\,\frac{\beta}{1-\beta^2}\,\frac{a}{(r^2+a^2)}\,dr&=&d\bar{\phi}&=& &d\breve{\phi}\,-\,\frac{1}{1+\beta}\,\frac{a}{(r^2+a^2)}\,dr \end{flalign}$$
This is it fixed.
$$\begin{align} dt\,+\,\frac{\beta}{1-\beta^2}\,dr&=d\bar{t}= d\breve{t}-\,\frac{1}{1+\beta}\,dr\\ d\phi\,+\,\frac{\beta}{1-\beta^2}\,\frac{a}{(r^2+a^2)}\,dr &= d\bar{\phi}= d\breve{\phi}\,-\,\frac{1}{1+\beta}\,\frac{a}{(r^2+a^2)}\,dr \end{align}$$

 

[m4r35n357]

I see a lot of broken Latex with FireFox
This is it fixed.
$$\begin{align} dt\,+\,\frac{\beta}{1-\beta^2}\,dr&=d\bar{t}= d\breve{t}-\,\frac{1}{1+\beta}\,dr\\ d\phi\,+\,\frac{\beta}{1-\beta^2}\,\frac{a}{(r^2+a^2)}\,dr &= d\bar{\phi}= d\breve{\phi}\,-\,\frac{1}{1+\beta}\,\frac{a}{(r^2+a^2)}\,dr \end{align}$$

Heh, I am already using those equations, they seem to work just fine ;) I just wanted to see how he puts it all together, it sounded interesting, and not too far above my level. BTW it looks just as broken in Chrome.