[Tex/LaTex] Package amsmath Error: Multiple \label’s: label ‘{33}’ will be lost

equations

I have this code and

Package amsmath Error: Multiple \label's: label '{33}' will be lost.

error: can anyone help me?

\begin{align}
\label{33}
\begin{split}
\alpha_{ng}^{\min}-\alpha_{ng}^{\max}+\gamma_n\leq C_{ng}\forall g\in\Omega^{G-n},\forall n\in\Omega^N
\end{split}
\label{34}
\begin{split}
\beta_\ell^{\min}-\beta_\ell^{\max}+\frac{\epsilon_\ell^{\min}}{\beta_\ell}-\frac{\epsilon_\ell^{\max}}{\beta_\ell}-\gamma_{n}=0
\forall l\in\Omega^L\mid \textit{FB}(\ell)=n
\end{split}
\\
\label{35}
\begin{split}
&\beta_\ell^{\min}-\beta_\ell^{\max}+\frac{\epsilon_\ell^{\min}}{\beta_\ell}-\frac{\epsilon_\ell^{\max}}{\beta_\ell}+\gamma_{n}=0\\
\forall \ell\in\Omega^L\mid \textit{TB}(\ell)=n
\end{split}
\\
\label{36}
\begin{split}
&-\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{FB}(\ell)=n}}}\epsilon_\ell^{\min}+\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{TB}(\ell)=n}}}\epsilon_\ell^{\min}
+\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{FB}(\ell)=n}}}\epsilon_\ell^{\max}-\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{TB}(\ell)=n}}}\epsilon_\ell^{\max}
+\\\delta_n^{\min}-\delta_n^{\max}=0~~\forall n\in \Omega^N
\end{split}
\\
\label{37}
&\gamma_n \leq \textit{VOLL}_n~~\forall n\in\Omega^N\\
\label{38}
&\bar{D}_{n}-\widehat D_{n}\leq\widetilde D_{n}\leq\bar{D}_{n}+\widehat D_{n}\\
\label{39}
&\sum_{ n\in\Omega^N}|\frac{\widetilde D_{n}-\bar D_{n}}{\widehat D_{n}}|\leq\textit{DR}
%\end{flalign}
\\
\label{40}
\begin{split}
&\alpha_{ng}^{\min},\alpha_{ng}^{\max}\geq 0\quad\forall g \in \Omega^{G-n},\forall n \in \Omega^{N};\\
\beta_\ell^{\min},\beta_\ell^{\max},  \epsilon_\ell^{\min},\epsilon_\ell^{\max}\geq 0\quad\forall l \in \Omega^{L};\\
\delta_n^{\min},\delta_n^{\max}\geq 0\quad\forall n \in \Omega^{N};
\gamma _n \in R\quad\forall n \in \Omega^{N};\\
\bar{D}_{n} \in R\quad\forall n \in \Omega^{N}\\
\end{split}
\end{align}

Best Answer

\begin{align}
\label{33}
\begin{split}
\alpha_{ng}^{\min}-\alpha_{ng}^{\max}+\gamma_n\leq C_{ng}\forall g\in\Omega^{G-n},\forall n\in\Omega^N
\end{split}
\\
\label{34}
\begin{split}
\beta_\ell^{\min}-\beta_\ell^{\max}+\frac{\epsilon_\ell^{\min}}{\beta_\ell}-\frac{\epsilon_\ell^{\max}}{\beta_\ell}-\gamma_{n}=0\\\forall l\in\Omega^L\mid \textit{FB}(\ell)=n
\end{split}
\\
\label{35}
\begin{split}
\beta_\ell^{\min}-\beta_\ell^{\max}+\frac{\epsilon_\ell^{\min}}{\beta_\ell}-\frac{\epsilon_\ell^{\max}}{\beta_\ell}+\gamma_{n}=0\\
\forall \ell\in\Omega^L\mid \textit{TB}(\ell)=n
\end{split}
\\
\label{36}
\begin{split}
-\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{FB}(\ell)=n}}}\epsilon_\ell^{\min}+\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{TB}(\ell)=n}}}\epsilon_\ell^{\min}
+\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{FB}(\ell)=n}}}\epsilon_\ell^{\max}-\smashoperator{\sum_{\substack{ \ell \in\Omega^L\st\\ \textit{TB}(\ell)=n}}}\epsilon_\ell^{\max}
+\\\delta_n^{\min}-\delta_n^{\max}=0~~\forall n\in \Omega^N
\end{split}
\\
\label{37}
&\gamma_n \leq \textit{VOLL}_n~~\forall n\in\Omega^N\\
\label{38}
&\bar{D}_{n}-\widehat D_{n}\leq\widetilde D_{n}\leq\bar{D}_{n}+\widehat D_{n}\\
\label{39}
&\sum_{ n\in\Omega^N}|\frac{\widetilde D_{n}-\bar D_{n}}{\widehat D_{n}}|\leq\textit{DR}
%\end{flalign}
\\
\label{40}
\begin{split}
&\alpha_{ng}^{\min},\alpha_{ng}^{\max}\geq 0\quad\forall g \in \Omega^{G-n},\forall n \in \Omega^{N};\\
&\beta_\ell^{\min},\beta_\ell^{\max},  \epsilon_\ell^{\min},\epsilon_\ell^{\max}\geq 0\quad\forall l \in \Omega^{L};\\
&\delta_n^{\min},\delta_n^{\max}\geq 0\quad\forall n \in \Omega^{N};
\gamma _n \in R\quad\forall n \in \Omega^{N};\\
&\bar{D}_{n} \in R\quad\forall n \in \Omega^{N}\\
\end{split}
\end{align}

Related Solutions

[Tex/LaTex] amsmath – multiple labels in one equation

According to p. 86 of the cleveref user guide,

With amsmath, the original \label command is stored in \ltx@label, and \label@in@display replaces \label inside [single-line] equations. \label@in@display just saves the label for later, and defining it is left until the end of the equation, when \ltx@label is finally called.

Hence, you may want to include the following code in the preamble, after loading the amsmath package:

\makeatletter
\let\ltxxlabel\ltx@label
\makeatother

so that you have a command that doesn't contain the "secret letter" @. Alternatively, you could execute the command \let\ltxxlabel\label before loading the amsmath package. Then, replace all \label commands in your document -- except, of course, those that are actually associated with equation numbers -- with \ltxxlabel.

I cannot try out this suggested solution myself since I don't have a clear idea as to how you use the \label command in your document for purposes other than creating associations with equation numbers. Nevertheless, I would encourage you to try out this method.

Addendum: The cleveref user guide has the following to say about the treatment of the \label macro in the multiline equation environments (such as gather, align, and multline) of the amsmath environment:

The amsmath multi-line equation environments scan their bodies twice: Once to measure, once to typeset. In the measure phase, the \label command is disabled by letting it to \@gobble. ... Unfortunately, amsmath wasn't designed with redefinitions of \label in mind ... The multline environment works a bit differently to the other amsmath environments, in that \label is disabled during the typesetting phase, and enabled during the measuring phase.

Given these observations, it would seem that only the adventurous and daring may want to delve into redefining the ways that amsmath works with the \label command in its multiline equation environments. I must admit to not being sufficiently daring, at least not in this category...

[Tex/LaTex] “!Missing $ inserted” error using amsmath environments

Many of amsmath environments are already in math mode.

This applies to the environments

equation,
align,
gather,
flalgin,
alignat and
multline

as well as their starred (unnumbered) versions.

The environment split is to be used inside amsmath environments and can be used to split one equation on more than one line (this important for the equation number).

The environments

aligned,
gathered and
alignedat

are similar to the version without -ed but are to be used in math mode.

As pointed out in the comments by Torbjørn T. empty lines aren’t allowed in math mode, they trigger the same error message.

amsmath’s environments (those who actually enter math mode) center their contents horizontally. The align family aligns its content internally at every odd &. See the example below how they work. You can use the fleqn option so that amsmath align the whole content of its environment at the left border (with a certain margin).

Code

\documentclass{article}
\usepackage{amsmath}
\usepackage{showframe}
\begin{document}
\begin{equation}
c^2 = a^2 + b^2
\end{equation}

\begin{gather}
            c^2 = a^2 + b^2 \\
a^2 + 2ab + b^2 = (a + b)^2
\end{gather}

\begin{align}
\text{right-aligned} & \neq \text{left-aligned} \nonumber\\
                 c^2 & = a^2 + b^2 \\
     a^2 + 2ab + b^2 & = (a + b)^2
\end{align}

\begin{align}
            c^2 & = a^2 + b^2 \\
\begin{split}
a^2 + 2ab + b^2 & = (a + b)^2 \\
                & = (a + b)(a + b) \\
                & = aa + ab + ba + bb \\
                & = a^2 + 2ab + b^2
\end{split}
\end{align}
\end{document}

Output

enter image description here