[Tex/LaTex] Writing a sequence of maps properly

Question

I wanna write the sequence $L \underset{\beta_1} \leftrightarrows \overset{ \alpha_1} M \underset{\alpha_2} \leftrightarrows \overset{ \beta_2} N$

with the map \alpha_1 above the arrows and \beta_1 below the arrows, same goes for \alpha_2 and \beta_2.

Any help please?

Answer 1

You can use:

\documentclass{standalone}
\usepackage{amsmath}
\begin{document} 
   $L \underset{\beta_1}{\overset{ \alpha_1} \leftrightarrow}  M
    \underset{\alpha_2}{\overset{ \beta_2} \leftrightarrow}  N$
\end{document}