# Problem with “numcases”

Please I need to create a formula with specific emplacements, something like

I used \usepackage{cases} with the "numcases" environment:

\documentclass{article}
\begin{document}
\usepackage{cases}

\begin{numcases}{}
\label{e2.1} ..........\\
\end{numcases}

\end{document}


I would like to get just three equations (2.1)-(2.3) where (2.1) is centered between the 2nd and 3rd lines, (2.2) centered between the 5th and 6th lines and finally (2.3) instead of (2.8) in the figure.

• So, a line in the cases should be made with aligned, for example, to group then. – Sigur Jan 4 '20 at 15:48

Something like this?

\documentclass[11pt,a4paper]{report}
\usepackage{amsmath}
\usepackage{cases}
\newcommand{\mydots}{\dots\dots}
\begin{document}
\begin{numcases}{}
\mydots\\
\begin{aligned}
\end{aligned}\\
\begin{aligned}
\end{aligned}\\
\end{numcases}
\end{document}

• Yes, I have to add "quad" to get my formula? there is a simplet method to get exactly the result of the figure ? – M.A Jan 4 '20 at 16:05
• @M.A Do you want a fixed width dots? – Sigur Jan 4 '20 at 16:07
• Yes please, but (1) and (3) with no numbers. – M.A Jan 4 '20 at 16:18
• @M.A, to remove a number, simply use \nonumber before \\. – Sigur Jan 4 '20 at 16:21

I'd use empheq that's much more powerful than cases.

Your requirement about equation numbers can be achieved by nesting aligned.

\documentclass{article}
\usepackage{empheq}

\begin{document}

\begin{empheq}[left=\empheqlbrace]{align}
& \mathstrut ..........
\label{e2.1}
\\
&\begin{aligned}
\end{aligned}
\label{e2.2}
\\
&\begin{aligned}
\end{aligned}
\label{e2.3}
\\
&\begin{aligned}