如何在數學顯示模式下編寫 a \tag，使其不會自動用括號括起來，並且 Overleaf 不會抱怨？ （我認為忽視 Overleaf 的抱怨是不好的做法。）
\documentclass{article}
\usepackage{amsmath, amssymb}
\begin{document}
The following would be perfect if the automatic parentheses enclosing the tag were removed:
\[J(2^m + l) = 2l + 1 \tag{for $m \geqq 0$ and $0 \leqq l < 2^m$}\]
The following output is good
\[J(2^m + l) = 2l + 1 \tag*{for $m \geqq 0$ and $0 \leqq l < 2^m$}\]
yet Overleaf complains about it; in particular, it introduces a red warning dot in the margin of the Code Editor, whose drop-down text reads:
\begin{verbatim}
unclosed open display math \[ found at $
unclosed open group { found at $
unexpected $ after open group {
unexpected $ after open display math \[
unexpected $ after open display math \[
unexpected $ after open display math \[
unexpected $ after open display math \[
\end{verbatim}
\end{document}
答案1
Overleaf 拒絕完全合法的 LaTeX 構造，這並不好。另一方面，您不應該在這種情況下濫用標籤，因為條件是等式的一部分，而標籤不是。
無論如何，你可以讓 Overleaf 保持安靜，使用\ttag定義為
\newcommand{\ttag}{\tag*}
避免在顯示前出現空白行，這是錯誤的。如果下一個文字開始一個新段落，則顯示後面可以有一個空白行。
\documentclass{article}
\usepackage{amsmath, amssymb}
\newcommand{\ttag}{\tag*}
\begin{document}
The following would be perfect if the automatic parentheses enclosing the tag were removed:
\[
J(2^m + l) = 2l + 1
\tag{for $m \geqq 0$ and $0 \leqq l < 2^m$}
\]
The following output is good
\[
J(2^m + l) = 2l + 1
\ttag{for $m \geqq 0$ and $0 \leqq l < 2^m$}
\]
But this output is much better
\[
J(2^m + l) = 2l + 1,
\qquad\text{for $m \geqq 0$ and $0 \leqq l < 2^m$}
\]
as you can clearly see, because the conditions are part of the equation.
\end{document}
Overleaf 視窗沒有顯示紅點。
