# centering environment - detach some text from centering

I'm trying to write some centered lines, but detach some of the text from the "centering" mechanism:

\begin{center}
some textual claim \\
$\Updownarrow$ \\
more text \\
$\Updownarrow$ - some comment \\
last text
\end{center}


I want the first Updownarrow to be over the second Updownarrow. How can I do that?

\begin{center}
$\Updownarrow$ \\
$\Updownarrow$\rlap{ - some comment} \\