I'm trying to create a system of equations with sub-numbering using the \begin{subnumcases} environment. Everything works perfectly but I would need to place a label somewhere in order to ref the system itself using the main number assigned to it, without having to ref one equation of it.
This is my code:
\documentclass{book}
\usepackage{cases}
\begin{document}
\begin{subnumcases}{}\label{eq:system}
\frac{d\psi}{d\zeta} = \frac{m_1}{y_1\prime}(x_1-\beta y_1\prime) \label{eq:dpsidz}
\\*
\frac{dx_i}{d\zeta} = \frac{m_i}{\psi y_i\prime}(x_i-y_i\prime)(x_i-\beta y_i\prime) \qquad \forall i=1,...,C-1 \label{eq:dxdz}
\\*
0 = y_1\prime (x_j-\beta y_j\prime)-\alpha_{1j}y_j\prime(x_1-\beta y_1\prime) \qquad \forall j=2,...,C \label{eq:algeb1}
\\*
0 = \sum_{i=1}^{C}y_i\prime -1 \label{eq:algeb2}
\\*
\psi|_{\zeta=0} = 1
\\*
x_i|_{\zeta=0} = x_i^F \qquad \forall i=1,...,C
\end{subnumcases}\\
The system illustrated in \ref{eq:system} is a \textsc{dae} system with a differential index equal to 1.
\end{document}
As you can see, I've tried to place the label{eq:system} inside the environment, before the first equation, but when I ref it in text it appears the name of the first equation. If the system equations are labelled 1.1a, 1.1b etc., I would like to ref the system as 1.1.
I hope I was clear in explaining my issue. Thank you
Best Answer
You can use
empheq
together withamsmath
and itssubequations
environment.With
hyperref
the anchor will be immediately above the system.A couple of stylistic notes:
...
you should input\dots
;\prime
you should use^{\prime}
or the easier'
(apostrophe) as in the code above.