In the example below (sorry, I don't know how to make it smaller), I try to include the page number in the equation numbering, but on top of a new page, the equation gets numbered by the previous page not by the page it is actually on. I indicate where the problem occurs with a sentence that references the incorrectly numbered equation. As you can see, on top of page 3, all 4 equations in the align
environment get numbered by the previous page.
I see the same problem with any theorem-like environment.
Motivation: it is much easier to find an equation (or any theoremlike structure) in a large article or book if the reference indicates the page number instead of the section or anything else.)
\documentclass[12pt,letterpaper]{amsart}
\numberwithin{equation}{page}
\begin{document}
\begin{equation}
\frac12=\frac24\label{eq:1}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:2}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:3}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:4}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:5}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:6}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:7}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:8}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:9}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:10}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:11}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:12}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:13}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:14}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:15}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:16}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:17}
\end{equation}
Equation \eqref{eq:17} is on page \pageref{eq:17}, not on the
previous page.
\begin{equation}
\frac12=\frac24\label{eq:18}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:19}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:20}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:21}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:22}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:23}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:24}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:25}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:26}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:27}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:28}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:29}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:30}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:31}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:32}
\end{equation}
\begin{align}
\frac12&=\frac24\label{eq:33} \\
\frac12&=\frac24\\
\frac12&=\frac24\\
\frac12&=\frac24
\end{align}
Equation \eqref{eq:33} is on page \pageref{eq:33}, not on the previous
page.
\begin{equation}
\frac12=\frac24\label{eq:34}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:35}
\end{equation}
\begin{equation}
\frac12=\frac24\label{eq:36}
\end{equation}
\end{document}
Added (thanks!!!): The perpage
package worked perfectly. One remark: it requires an extra run of latex. I could even use it for theoremlike environments. Here is what I needed to do to have all theorems be numbered by page. Note that the counter redefinition had to be done after the definition of the thm
environment since the counter thm
counter doesn't exist before.
\mdtheorem[style=theorem]{thm}{Theorem}
\let\origthethm\thethm
\MakePerPage{thm}
\renewcommand{\thethm}{\theperpage.\origthethm}
\label{eq:1}
system is only used to track the equations here in demonstration, not in your real document\pageref