How can I create a list of equations in an equation environment?

Question

I am trying to create something like this in amsart document class:

where I can label and access the individual equations through the \label and \ref commands.

I have tried various combinations of the align, equation, aligned, cases, and array environments, but either I am making a mistake (which is very likely) or it is more complicated than I thought.

I sincerely hope that someone among you can help me in some way. Thank you in advance.

This question might help: Separate labels in cases – barbara beeton Jan 07 '24 at 18:59 — barbara beeton, Jan 07 '24 at 18:59
Does this answer your question? Separate labels in cases – Elad Den Jan 10 '24 at 08:26 — Elad Den, Jan 10 '24 at 08:26

John Kormylo · Accepted Answer · 2024-01-08T00:42:24.763

\label and \ref are used for counters, specifically the last occurance of \refstepcounter. However, equation redefines \label to always return the equation number.

This uses a new counter (case) to generate the case numbers so that \label can record them. It also uses \normallabel, which is simply \label as defined outside the equation environment.

I put the parenthesis inside \thecase for simplicity.

\documentclass[leqno]{amsart}
\newcounter{case}[equation]% reset to 0
\renewcommand{\thecase}{\textrm{(\roman{case})}}
\let\normallabel=\label
\begin{document}
\begin{equation}
\begin{cases}
  \refstepcounter{case}\hfil\thecase\normallabel{first} & first\
  \refstepcounter{case}\hfil\thecase\normallabel{second} & second\
  \refstepcounter{case}\hfil\thecase\normallabel{third} & third
\end{cases}
\end{equation}
See cases \ref{first}, \ref{second} and \ref{third}.
\end{document}

How can I create a list of equations in an equation environment?

1 Answers1