ミニページで方程式の周囲の垂直間隔を維持するにはどうすればよいですか?

Question

次の例:

\documentclass{standalone}

\begin{document}
% outer minipages are not part of the test, and just demonstrate the inconsistency
\begin{minipage}[t]{0.5\textwidth}
    
    This is an equation
    \begin{equation}
        x = 1,
    \end{equation}
    which ends in a comma.
    
\end{minipage}%
\begin{minipage}[t]{0.5\textwidth}
    
    This is a minipage equation\par
    \begin{minipage}[t]{\textwidth}
        \begin{equation}
            x = 1,
        \end{equation}
        \par\nointerlineskip\xdef\tpd{\the\prevdepth}
    \end{minipage}%
    \par\prevdepth\tpd\noindent
    which ends in a comma.
    
\end{minipage}%

\end{document}

どこprevdepthから原料が採取されるかhttps://tex.stackexchange.com/a/34982/41112は次のように表示されます

ミニページを削除せずに、右側の列を左側の列と一致させるにはどうすればよいですか? $x=1$ の行も、ごくわずかではありますが、位置がずれていることに注意してください。

---

編集: これは XY 問題であることが判明し、上記の私の質問に対する解決策は実際の問題には機能しません。つまり、

\documentclass{article}
\usepackage{amsmath}
\usepackage{xcolor}

\begin{document}

This is some text that is long enough to wrap across multiple lines, or at least it ought to be. This gap is too big:\par\nointerlineskip\noindent
\begin{minipage}[t]{.5\textwidth}%
    \begin{subequations}\label{eq:tensor_tensor_tensor_left}%
    \begin{alignat}{2}%
    &
        (M \otimes_{\color{red} R} N) \otimes_{\color{blue} A} (P \otimes_{\color{red} R} Q) \nonumber \\
    \cong_{\color{blue} A} {}&
        ((M \otimes_{\color{red} R} N) \otimes_{\color{blue} A} P) \otimes_{\color{red} R} Q) \label{eq:ttt-left-assoc-1}
    \end{alignat}%
    \end{subequations}%
\end{minipage}%
\begin{minipage}[t]{.5\textwidth}%
    \begin{subequations}\label{eq:tensor_tensor_tensor_right}%
    \begin{alignat}{2}%
    &
        (M \otimes_{\color{red} R} N) \otimes_{\color{blue} A} (P \otimes_{\color{red} R} Q) \nonumber \\
    \cong_{\color{blue} A} {}&
        M \otimes_{\color{red} R} (N \otimes_{\color{blue} A} (P \otimes_{\color{red} R} Q) \label{eq:ttt-right-assoc-1}
    \end{alignat}%
    \end{subequations}%
  \par\xdef\tpd{\the\prevdepth}%
  \vspace*{\belowdisplayskip}\vspace*{-\baselineskip}%
  \end{minipage}\par\prevdepth=\tpd\noindent
and some more unindented text. The gap above is too small. Toegther they add to the right amount.
\begin{alignat}{2}%
&
    (M \otimes_{\color{red} R} N) \otimes_{\color{blue} A} (P \otimes_{\color{red} R} Q) \nonumber \\
\cong_{\color{blue} A} {}&
    M \otimes_{\color{red} R} (N \otimes_{\color{blue} A} (P \otimes_{\color{red} R} Q) \label{eq:ttt-right-assoc-1}
\end{alignat}%
These two gaps are just right, and is a bit bigger than the one above

\end{document}

これにより、次のようになります。

Answer 1

例を修正して、2 番目の外側のミニページは、最初のミニページと並べて効果を示すためだけのものになるようにします。2 番目のミニページでは、最初の行と数式がミニページ内にあり、それに続くテキストは外側にあります。

\documentclass{article}

\begin{document}
% outer minipages are not part of the test, and just demonstrate the inconsistency
\noindent
\begin{minipage}[t]{0.5\textwidth}
  This is an equation
  \begin{equation}
    x = 1,
  \end{equation}
  which ends in a comma.
\end{minipage}%
\begin{minipage}[t]{0.5\textwidth}
  \begin{minipage}[t]{\linewidth}
    This is a minipage equation
        \begin{equation}
            x = 1,
        \end{equation}
  \par\xdef\tpd{\the\prevdepth}%
  \vspace*{\belowdisplayskip}\vspace*{-\baselineskip}
  \end{minipage}\par\prevdepth=\tpd
   which ends in a comma.
\end{minipage}

\end{document}

ただし、これはいくつかの点で失敗する可能性があります。なぜなら、式の後のスキップが発生する可能性があり\belowdisplayshortskip、それを確認するにはかなり複雑なルーチンが必要になるからです。

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関して本物問題に対処するには、次のようにすることをお勧めしますhttps://tex.stackexchange.com/a/550010/4427

\mathcolor{red}{R}を優先します\color{red} R。

\documentclass{article}
\usepackage{amsmath}
\usepackage{xcolor}

\newcommand{\sidebysidesubequations}[5][0.5]{%
  $$% Yes! We're consciously doing it
  \begin{minipage}{#1\displaywidth}%
  \setlength{\abovedisplayskip}{0pt}%
  \begin{subequations}\label{#2}
  \noindent#3
  \end{subequations}
  \end{minipage}
  \begin{minipage}{\dimeval{\displaywidth-#1\displaywidth}}
  \setlength{\abovedisplayskip}{0pt}%
  \begin{subequations}\label{#4}
  \noindent#5
  \end{subequations}
  \end{minipage}
  $$%
}

\begin{document}

This is some text that is long enough to wrap across multiple lines, or 
at least it ought to be.
\sidebysidesubequations{eq:tensor_tensor_tensor_left}{
  \begin{align}
    & (M \otimes_{\mathcolor{red}{R}} N)
    \otimes_{\mathcolor{blue}{A}}
    (P \otimes_{\mathcolor{red}{R}} Q) \nonumber \\
  \cong_{\mathcolor{blue}{A}} {}&
    M \otimes_{\mathcolor{red}{R}}
    (N \otimes_{\mathcolor{blue}{A}} (P \otimes_{\mathcolor{red}{R}} Q) \label{eq:ttt-left-assoc-1}
 \\
    & (M \otimes_{\mathcolor{red}{R}} N)
    \otimes_{\mathcolor{blue}{A}}
    (P \otimes_{\mathcolor{red}{R}} Q) \nonumber \\
  \cong_{\mathcolor{blue}{A}} {}&
    M \otimes_{\mathcolor{red}{R}}
    (N \otimes_{\mathcolor{blue}{A}} (P \otimes_{\mathcolor{red}{R}} Q) \label{foo1}
  \end{align}
}{eq:tensor_tensor_tensor_right}{
  \begin{align}
    & (M \otimes_{\mathcolor{red}{R}} N)
    \otimes_{\mathcolor{blue}{A}} (P \otimes_{\mathcolor{red}{R}} Q) \nonumber \\
  \cong_{\mathcolor{blue}{A}} {}&
      M \otimes_{\mathcolor{red}{R}}
  (N \otimes_{\mathcolor{blue}{A}} (P \otimes_{\mathcolor{red}{R}} Q) \label{eq:ttt-right-assoc-1}
  \\
    & (M \otimes_{\mathcolor{red}{R}} N)
    \otimes_{\mathcolor{blue}{A}} (P \otimes_{\mathcolor{red}{R}} Q) \nonumber \\
  \cong_{\mathcolor{blue}{A}} {}&
      M \otimes_{\mathcolor{red}{R}}
  (N \otimes_{\mathcolor{blue}{A}} (P \otimes_{\mathcolor{red}{R}} Q) \label{foo2}
  \end{align}
}
and some more unindented text
and some more unindented text
and some more unindented text
and some more unindented text.
\begin{align}
  & (M \otimes_{\mathcolor{red}{R}} N)
    \otimes_{\mathcolor{blue}{A}} (P \otimes_{\mathcolor{red}{R}} Q) \nonumber \\
  \cong_{\mathcolor{blue}{A}} {}&
    M \otimes_{\mathcolor{red}{R}}
    (N \otimes_{\mathcolor{blue}{A}}
    (P \otimes_{\mathcolor{red}{R}} Q) \label{eq:ttt-right-assoc-2}
  \end{align}
These two gaps are just right, and is a bit bigger than the one above

\end{document}