Is there any simple (method/macro,..) to replace everything inside all eqnarray* by a simple given text. More precisely
for example I want to replace
\begin{eqnarray*}
x & = & \frac{1}{2}at_1^2 + v_0t_1 + x_0\\
t_1^2 & = & \frac{2x}{g}
\end{eqnarray*}
or any eqnarray* by
\begin{eqnarray*}
\text{Math inside}
\end{eqnarray*}
best regards.
Edit: it would be nice if this also works for align, displaymath,....
It should save the environment structure, and replace the content inside it.

eqnarray... See why here: http://www.tug.org/TUGboat/tb33-1/tb103madsen.pdf. Then, what you want is: whenever you use one of those environments, you want a simple text to be printed instead of its contents? – karlkoeller Nov 19 '13 at 15:05