I am currently showing that $a=b\Leftrightarrow e=f$ by showing that $a=b\Leftrightarrow c=d\Leftrightarrow e=f$. The problem that I have is that the expressions $\{a,b,c,d,e,f\}$ are rather long and do not fit in a single line. I am currently writing this: \begin{gather} a=b\\ c=d\\ e=f \end{gather} But I am wondering whether I should instead write this: \begin{gather} a=b\Leftrightarrow\\ c=d\Leftrightarrow\\ e=f \end{gather} Or perhaps even this: \begin{gather} a=b\Leftrightarrow\\ \Leftrightarrow c=d\Leftrightarrow\\ \Leftrightarrow e=f \end{gather} Hence, how should I write $a=b\Leftrightarrow c=d\Leftrightarrow e=f$ if the expression does not fit a single line?
Thank you all in advanced for your time!