对于以下代码：
\documentclass[12pt]{report}
\usepackage[utf8]{inputenc}
\usepackage{setspace}
\usepackage{graphicx}
\include{\frontmatter/title}
\include{\frontmatter/abstract}
\include{\frontmatter/declaration}
\include{\frontmatter/quotation}
\include{\frontmatter/acknowledgements}
\end{document}
我收到此错误：
main.tex, line 7
Undefined control sequence.
<write> \string \@input {\frontmatter /title.aux}
l.7 \include{\frontmatter/title}
The control sequence at the end of the top line
of your error message was never \def'ed. If you have
misspelled it (e.g., `\hobx'), type `I' and the correct
spelling (e.g., `I\hbox'). Otherwise just continue,
and I'll forget about whatever was undefined.
答案1
OP\include与另一份完整文档一起使用，即在声明\documentclass中使用完整的序言\include{foo}。
这行不通，至少这种方式不行。对于特殊用途，combine可以使用该包。
此外，在\included 文件中，\chapter不应出现等情况。
由于没有提供更多信息，所以除了阅读入门级 LaTeX 书籍之外没有其他建议。楼主已经有半年没有回来了。