# How to make a system of equations with a number after every line and a tall curly brace on the left [duplicate]

So, i have this code:

\begin{align}
S(t+\Delta) &= S(t)-\beta S(t)I(t)\Delta + \phi R(t) \Delta \label{S}\\
I(t+\Delta) &= I(t) + \beta S(t)I(t) \Delta - \gamma I(t) \Delta \label{I}\\
R(t+\Delta) &= R(t) + \gamma I(t)\Delta - \phi R(t)\Delta \label{R} \end{align}


I want this with the numbering after every line (i already have that); but i want an '{' in front of the three lines. Is that possible?

## marked as duplicate by barbara beeton, TeXnician, user156344, user36296, MenschMar 31 at 15:00

\documentclass{article}
\begin{document}
ABC
\begin{align}[left=\empheqlbrace]
S(t+\Delta) &= S(t)-\beta S(t)I(t)\Delta + \phi R(t) \Delta \label{S}\\
I(t+\Delta) &= I(t) + \beta S(t)I(t) \Delta - \gamma I(t) \Delta \label{I}\\
R(t+\Delta) &= R(t) + \gamma I(t)\Delta - \phi R(t)\Delta \label{R}
\end{align}
From equation \eqref{S}, \eqref{I} and \eqref{R}, we have blah blah blah
\end{document} • The referenced question is already listed as a duplicate to Separate labels in cases. So this question should probably also be marked a duplicate. – barbara beeton Mar 31 at 14:03
• @barbarabeeton I do think this question is a duplicate of the linked question, but not Separate labels in cases. – user156344 Mar 31 at 14:20