# Re: centered formulas + \iff

On 05/06/2016 22:41, Paul A. Rubin wrote:

Kiuhnm <kiuhnm2015 <at> gmail.com> writes:



I came up with a (not so clean) solution:



Try replacing everything between \begin_body and \end_body with the
following and see if it looks right:

\begin_layout Standard
\begin_inset Formula
\begin{alignat*}{3}
H(Z) & \leq\mathbb{E}_{Z}\lceil I(Z)\rceil &  & <H(Z)+1 & \iff\\
nH(X) & \leq\mathbb{E}_{Z}\lceil I(Z)\rceil &  & <nH(X)+1 & \iff\\
H(X) & \leq\frac{\mathbb{E}_{Z}\lceil I(Z)\rceil}{n} &  & <H(X)+\frac{1}{n}.
\end{alignat*}

\end_inset

\end_layout

It uses an alignat environment with three columns added (raising the total
from the default two to five), leaving the third column empty (so that the
last expressions before \iff align left rather than right).



Close, but not perfect. For the central part we need gather(ed). There's no escaping it. Compare:

\begin_body

\begin_layout Standard
\begin_inset Formula
\begin{alignat*}{3}
H(Z) & \leq\mathbb{E}_{Z}\lceil I(Z)\rceil &  & <H(Z)+1 & \iff\\
nH(X) & \leq\mathbb{E}_{Z}\lceil I(Z)\rceil &  & <nH(X)+1 & \iff\\
H(X) & \leq\frac{\mathbb{E}_{Z}\lceil I(Z)\rceil}{n} &  & <H(X)+\frac{1}{n}.
\end{alignat*}

\end_inset

\end_layout

\begin_layout Standard
\begin_inset Formula
\begin{alignat*}{2}
\begin{aligned}H(Z)\leq\vphantom{\mathbb{E}_{Z}\lceil I(Z)\rceil}\\
nH(X)\leq\vphantom{\mathbb{E}_{Z}\lceil I(Z)\rceil}\\
H(X)\leq\vphantom{\frac{\mathbb{E}_{Z}\lceil I(Z)\rceil}{n}}
\end{aligned}
& \begin{gathered}\mathbb{E}_{Z}\lceil I(Z)\rceil\\
\mathbb{E}_{Z}\lceil I(Z)\rceil\\
\frac{\mathbb{E}_{Z}\lceil I(Z)\rceil}{n}
\end{gathered}
& \begin{aligned} & \vphantom{\mathbb{E}_{Z}\lceil I(Z)\rceil}<H(Z)+1\\
& \vphantom{\mathbb{E}_{Z}\lceil I(Z)\rceil}<nH(X)+1\\
& \vphantom{\frac{\mathbb{E}_{Z}\lceil I(Z)\rceil}{n}}<H(X)+\frac{1}{n}.
\end{aligned}
& \begin{gathered}\vphantom{\mathbb{E}_{Z}\lceil I(Z)\rceil}\iff\\
\vphantom{\mathbb{E}_{Z}\lceil I(Z)\rceil}\iff\\
\vphantom{\frac{\mathbb{E}_{Z}\lceil I(Z)\rceil}{n}}
\end{gathered}
\end{alignat*}

\end_inset

\end_layout

\end_body