# How do you make \Rightarrow and \Leftarrow aligned parallel under \begin{proof}?

Here is what I'm trying to type.

\begin{proof}

\begin{enumerate}

\item[$\Rightarrow$] bla bla bla

\item[$\Leftarrow$] bla bla bla

\end{enumerate}

\end{proof}


But, if I try that, I can't get $\Rightarrow$ and $\Leftarrow$ parallel to make them look nice, if you know what you mean,,,;; (the $\Rightarrow$ is just on the right of the title "proof", while $\Leftarrow$ is not aligned vertically with $\Rightarrow$ since $\Leftarrow$ is aligned vertically with "proof"...)

How, do I make them parallel to make them look nice?

• My advice is to forget enumerate. Just \begin{proof}($\Rightarrow$)...<empty line>($\Leftarrow$)...\end{proof}. The arrows already give sufficient visual clues. – egreg Aug 29 '14 at 19:40

You should have some thing written directly after the Proof. word and before the enumerate environment. So, using a ~ will do the job.

\documentclass[12pt]{article}
\usepackage{amsmath}
\usepackage{amsthm}
\begin{document}

\begin{proof}~
\begin{enumerate}
\item[$\Rightarrow$] bla bla bla
\item[$\Leftarrow$]  bla bla bla
\end{enumerate}
\end{proof}

\end{document}


The output:

• suggest that you use \qedhere before the \end{enumerate} to move the "tombstone" up to the last line of the list. in any event, remove the blank line before \end{proof}; otherwise, the "tombstone" could break to a new page if the proof happens to come at the end of a page. – barbara beeton Aug 29 '14 at 19:43