How to start subequations with a known number?

Question

I want my subequations starting with number (9u).

How can I do this?

I have a long list of subequations which cannot fit into a single page. The first part of subequations ends with (9t). I am trying to write the second part at second page as new subequations starting with (9u). — user3489173, Oct 15 '20 at 23:06
There is no restriction on subequations: it can span several pages. You've possibly asked the wrong question: maybe you need to split a long align or similar environment across pages. — egreg, Oct 15 '20 at 23:08
\begin{figure} \begin{subequations} { .... } \end{subequations} \end{figure} .I have to use figure{*} which does allows\displaybreak. but does not make any split! — user3489173, Oct 15 '20 at 23:14

score 0 · Accepted Answer · answered Oct 15 '20 at 23:19

Not sure why you would do it, but here it is.

\documentclass{article}
\usepackage{amsmath}
\newcounter{storesubequations}
\begin{document}
\begin{equation}
y
\end{equation}
\begin{subequations}
\begin{align}
a&=b \
c&=d
\end{align}%
\setcounter{storesubequations}{\value{equation}}%
\end{subequations}
\addtocounter{equation}{-1}
\begin{subequations}\setcounter{equation}{\value{storesubequations}}
\begin{align}
e&=f \
g&=h
\end{align}
\end{subequations}
\begin{equation}
y
\end{equation}
\end{document}

How to start subequations with a known number?

1 Answers1