在测试一些新环境时，我犯了这样的错误：
...
\begin{document}
...
\begin{A}
...
\end{A}
...
\begin{B}
...
\end{A}
...
\end{document}
LaTeX 抱怨说结束B时没有结束document。它谈论了行在哪里\end{document}，以及行在哪里\begin{B}，但它确实不是谈论不匹配\end{A}（实际错误的位置）。
为什么 LaTeX 无法检测到这种情况？我知道\newenvironment实际上定义了两个命令，一个用于开始，一个用于结束，但是难道它不能检测到从未开始过的事情即将结束的情况吗？
更新 1：
我给出的例子（据我所知）是问题的本质，我在头脑中构建了它，因为原始文件有数千行和许多图形等（太多了，无法在这里展示，而且也是由 TeX analphabet 编写的，所以你会抓狂地看到我的挣扎......）。但人们不相信我写的东西。所以我从我的大文件中制作了一个小测试文件，展示了这个问题：
以下是输入的重要部分：
\begin{gfxTableCap}[p]{lr}{Caption}{label2}%
\gfxCap{0.4}{Platzhalter.pdf}{Caption 2A}
&
\gfxCap{0.4}{Platzhalter.pdf}{Caption 2B}
\end{gfxTableCapLab}
导致此输出（截断为本质）：
This is pdfTeX, Version 3.14159265-2.6-1.40.18 (TeX Live 2017/TeX Live for SUSE Linux) (preloaded format=pdflatex)
restricted \write18 enabled.
entering extended mode
(./xxx.tex
LaTeX2e <2017-04-15>
[...]
<Platzhalter.pdf, id=1, 284.52756pt x 227.62204pt> <use Platzhalter.pdf>
<use Platzhalter.pdf> <use Platzhalter.pdf> <use Platzhalter.pdf>
! LaTeX Error: \begin{gfxTableCap} on input line 88 ended by \end{document}.
See the LaTeX manual or LaTeX Companion for explanation.
Type H <return> for immediate help.
事实确实如此不是说“出乎意料” \end{gfxTableCapLab}。
如果它对于我定义的环境来说很特殊，那么情况就是如此混乱：
\documentclass[a4paper,twoside]{report}
\newcommand{\gtLab}{}
\newcommand{\gtCap}{}
\newenvironment{gfxTableCapLab}[4][htbp]{%
\begin{figure}[#1]%
\begin{tabular}{#2}}%
{\end{tabular}%
\gtCap%
\end{figure}%
}
\newenvironment{gfxTableCap}[3][htbp]{%
\begin{gfxTableCapLab}{#2}{#3}{}%
}%
{\end{gfxTableCapLab}}
\newenvironment{gfxTableLab}[3][htbp]{%
\begin{gfxTableCapLab}{#2}{}{#3}%
}%
{\end{gfxTableCapLab}}
\newenvironment{gfxTable}[2][htbp]{%
\begin{gfxTableCapLab}{#2}{}{}%
}%
{\end{gfxTableCapLab}}
\newcommand{\gLab}{}
\newcommand{\gCap}{}
\newcommand{\gfxCapLab}[4]{%
\begin{minipage}[t]{#1\textwidth}%
{graphic}%
\gCap%
\end{minipage}
}
\newcommand{\gfxCap}[3]{\gfxCapLab{#1}{#2}{#3}{}}
\begin{document}
Some text...
\begin{gfxTableCapLab}[p]{lr}{Caption}{label1}%
\end{gfxTableCapLab}
%
Text
\begin{gfxTableCap}[p]{lr}{Caption}{label2}%
\end{gfxTableCapLab}
\end{document}
对于没有合适占位符 PDF 的所有人，这里是 uuencoded 版本（我无法将 PDF 作为图像附加）：
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end
答案1
请始终发布实际的测试文档，而不是无法测试的片段。一般来说，LaTeX 会在
\end{A}
但有些情况下不能这样做，例如，如果B是，verbatim那么根据定义，所有处理都将被禁用，直到\end{B}看到，在这种情况下，该错误只会在文件末尾检测到。
所以
\documentclass{article}
\begin{document}
\begin{empty}
\end{empty}
\begin{quad}
\end{empty}
\end{document}
在第 11 行产生错误消息
! LaTeX Error: \begin{quad} on input line 9 ended by \end{empty}.
See the LaTeX manual or LaTeX Companion for explanation.
Type H <return> for immediate help.
...
l.11 \end{empty}
但
\documentclass{article}
\begin{document}
\begin{empty}
\end{empty}
\begin{verbatim}
\end{empty}
\end{document}
在文件末尾产生错误
Runaway argument?
^^M^^M\end{empty}^^M^^M^^M\end{document}^^M
! File ended while scanning use of \@xverbatim.
<inserted text>
\par
<*> bb469
?
查看提供的具体示例，请注意 tex 是一个宏扩展系统而不是编译器，它永远不会提前解析完整的文档。
所以从
\begin{gfxTableCap}[p]{lr}{Caption}{label2}%
\end{gfxTableCapLab}
\end{document}
\gfxTableCap 经过最初的几次扩张之后
\begin{gfxTableCapLab}{p}{lr}{Caption}%
\end{gfxTableCapLab}
\end{document}
\end{gfxTableCapLab}因此，文档中明确指出 关闭了内部环境，但外部环境gfxTableCap从未关闭，并且直到此处的包含组关闭后才能检测到\end{document}。