Most extraction tools treat a displayed equation as an ordinary text line. That works when the expression is short and linear, like the examples below, but it breaks as soon as a fraction, exponent stack, or integral needs two-dimensional layout.

$$
\[\mathsf{E}=\mathsf{m}\mathsf{c}\mathsf{^2}\]
$$

$$
\[a^{\wedge}2+b^{\wedge}2=c^{\wedge}2\]
$$

$$
\[\mathsf{f}(\mathsf{x})=3\mathsf{x}+7\]
$$

$$
\[\mathsf{s u m}_{\_}\{i=1\}^{\wedge}\{n\}x\textsubscript{_}i\]
$$