Title: ??? with align/split environment
Last modified: December 27, 2018

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# ??? with align/split environment

 *  Resolved [vesnog](https://wordpress.org/support/users/vesnog/)
 * (@vesnog)
 * [7 years, 5 months ago](https://wordpress.org/support/topic/with-align-split-environment/)
 * Hello,
 * I recently started using LaTeX2HTML plugin in order to publish scientific content
   on my blog. However, when I use complex equations with split/align environments
   from **amsmath** package I have problems referring to these equations later on
   as instead of an equation number ??? is displayed. This is not the case with 
   single line simple equations and they are correctly referenced with **\eqref **
   command.
 * I browsed through the PHP files in the hope that I will point me in the right
   direction, yet failed as I do not know PHP. The way I use split environment is
   inside a parent equation environment just like I do in regular LaTeX with pdflatex
   as the compiler.
 * `\begin{equation}\label{eq:Polarization}<br>\begin{split}<br>P_{induced} &= Np\\
   <br>&= -Nex \\<br>&= \frac{Ne^2}{m_0}\frac{1}{(\omega_0^2-\omega^2 - i \gamma\
   omega)} \mathrm{E}<br>\end{split}<br>\end{equation}`
 * I appreciate your assistance and explanation on this matter. Furthermore, is 
   it normal that Latex comments starting with % are displayed as they are on the
   output?
 * The page I need help with: _[[log in](https://login.wordpress.org/?redirect_to=https%3A%2F%2Fwordpress.org%2Fsupport%2Ftopic%2Fwith-align-split-environment%2F%3Foutput_format%3Dmd&locale=en_US)
   to see the link]_

Viewing 1 replies (of 1 total)

 *  Plugin Author [Van Abel](https://wordpress.org/support/users/van-abel/)
 * (@van-abel)
 * [7 years, 5 months ago](https://wordpress.org/support/topic/with-align-split-environment/#post-11032015)
 * 1. The LaTeX2HTML plugin of version newer than v2.0.0 do nothing to the labeling/
   referencing stuff, which is done by MathJax.
 * So your problem is related to MathJax, and the `bug` seems has a workaround as
   mentioned here, [Referring to labels defined in an expression with “split” or “aligned” environments seems broken](https://github.com/mathjax/MathJax/issues/1020):
 * which is simple, just move your label at the bottom of split:
 *     ```
       \begin{equation}
       \begin{split}
       P_{induced} &= Np \\
       &= -Nex \\
       &= \frac{Ne^2}{m_0}\frac{1}{(\omega_0^2-\omega^2 - i \gamma \omega)} \mathrm{E}
       \end{split}
       \label{eq:Polarization}
       \end{equation}
       \eqref{eq:Polarization}
       ```
   
 * 2. Furthermore, is it normal that Latex comments starting with % are displayed
   as they are on the output?
 * Of course not, the lines start with `%` should understand as comment out, thus
 *     ```
       % this is comment out
       % This is comment out too
       ```
   
 * will be hidden completely on the output. This is what LaTeX2HTML expect and actually
   do.
    -  This reply was modified 7 years, 5 months ago by [Van Abel](https://wordpress.org/support/users/van-abel/).
    -  This reply was modified 7 years, 5 months ago by [Van Abel](https://wordpress.org/support/users/van-abel/).

Viewing 1 replies (of 1 total)

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 * 1 reply
 * 2 participants
 * Last reply from: [Van Abel](https://wordpress.org/support/users/van-abel/)
 * Last activity: [7 years, 5 months ago](https://wordpress.org/support/topic/with-align-split-environment/#post-11032015)
 * Status: resolved