我正在尝试使用大学要求的文档类来撰写我的论文，并在 overleaf 中工作（大学也建议这样做）。奇怪的是，数学模式中的撇号 (') 未打印在输出 pdf 中。请参见下图。
这当然是个大问题。如果我在 Overleaf 中打开另一个简单的 tex 文件并使用数学模式，那么一切都会正常进行。
以下是我正在使用的软件包。前几个软件包（没有说明）来自我想要包含在论文中的论文。其余的是大学提供的模板的一部分。有人知道问题可能是什么吗？
\usepackage{amsmath,amssymb,amsthm, bm}
\usepackage{enumerate}
%\usepackage{marginfix}
\usepackage{cite}
\usepackage{xcolor}
\usepackage{hyperref}
\usepackage{graphicx}
\usepackage[normalem]{ulem}
\usepackage{tikz}
\usepackage[spanish, english]{babel}
%\usepackage[ansinew]{inputenc}
\usepackage{here}
% PurdueThesis.cls loads the rotating package which loads the graphicx
% package. From
% Packages in the `graphics' bundle
% at
% http://ftp.math.purdue.edu/mirrors/ctan.org/macros/latex/required/graphics/grfguide.pdf
% on page 12
% \graphicspath{<dir-list>}
% This optional declaration may be used to specify a list of
% directories in which tosearch for graphics files. The
% format is the same as for the LATEX 2e primitive\input@path.
% A list of directories, each in a{}group (even if there is
% only one in the list). For
% example:\graphicspath{{eps/}{tiff/}}would cause the system
% to look in the subdirectories eps and tiff of the
% currentdirectory. (All modern TeX systems use / as the
% directory separator, even on Windows.) The default setting of
% this path is \input@path that is: graphics files will be found
% whereever TeX files are found.
%
% Look in the "graphics" subfolder for graphics files.
% This is done to reduce the number of files in the main thesis folder
% so the ones in there are easier to find.
\graphicspath{{graphics/}}
% Look in the "packages" subfolder for packages.
% This is done to reduce the number of files in the main thesis folder
% so the ones in there are easier to find.
\makeatletter
\def\input@path{{packages/}}
\makeatother
%
% Configure bibliography.
%
% Automatically configure the bibliography. Based on the
% institution, campus, and program listed in the \documentclass
% command \bibprocessor is set to "biblatex" or "bibtex".
% For biblatex, a
% \usepackage[...]{biblatex}
% is done. Put your bibliography entries in all-biblatex.bib.
% For bibtex, a
% \bibliographystyle{...}
% command is done. Put your bibliography entries in all-bibtex.bib.
%
% All combinations of institution, campus, and program use biblatex.
% Exceptions that use bibtex:
% o "Purdue University", "West Lafayette", "Earth, Atmospheric,
% and Planetary Sciences" uses the ametsoc2014 bibliography style.
% o "Purdue University", "West Lafayette", "Veterinary Clinical
% Sciences" uses the ama bibliography style.
%
% To override the default choices picked by \ConfigureBibliography, change,
% for example,
% \ConfigureBibliography
% to
% % \ConfigureBibliography
% \newcommand{\bibprocessor}{biblatex}
% \usepackage[backend=biber, citestyle=apa, dashed=false, sortcites=true, style=apa]{biblatex}
% \addbibresource{all-biblatex.bib}
\ConfigureBibliography
%
% This is only relevant if you are using biblatex.
%
% This is an example of how to ignore urldate fields in your .bib file.
% See the first complete example on page 201 of
% https://mirrors.rit.edu/CTAN/macros/latex/contrib/biblatex/doc/biblatex.pdf
%
% If you don't want to ignore urldate fields,
% comment out (put "%" before) the next ten lines.
%
\ifthen{\equal{biblatex}{\bibprocessor}}
{
\DeclareSourcemap{
\maps[datatype=bibtex]{
\map{
\step[fieldset=urldate, null]
}
}
}
}
% For chemical figures, \chemfig.
%\usepackage{chemfig}
% For \VerbatimInput.
\usepackage{fancyvrb}
% https://andreas.scherbaum.la/blog/archives/670-Read-number-lines-in-a-file-in-LaTeX.html
% Indent verbatim by 23.5pt so line numbers are within margin.
\makeatletter
\@totalleftmargin=23.5pt
\makeatother
% pages 11--12.
\usepackage{cancel}
% This gets rid of
% [5] (./thesis.toc
% ! Undefined control sequence.
% \vbox_set:Nn ...box:D {\color_group_begin: #2\par
% \color_group_end: }
% l.32 ...}Basic Circuit Components}{31}{section.67}
% %
% ?
% and
% [6]
% ! Undefined control sequence.
% \vbox_set:Nn ...box:D {\color_group_begin: #2\par
% \color_group_end: }
% l.61 ...rline {P.1}Frenchspacing}{67}{section.445}
% %
% ?
% errors.
% See
% https://github.com/latex3/latex2e/issues/73
\usepackage{etoc}
% For indexing. Making an index is optional.
% Make these commands available:
% COMMAND DESCRIPTION
% \index{string} put "string" in index information
% \makeindex save information to make the index
% \printindex print the index
% See
% https://ctan.org/pkg/makeidx?lang=en
% for more information.
\usepackage{makeidx}
% By default \index ignores its argument.
% This activates indexing.
\makeindex
% The "chapter name" for the index.
\renewcommand{\indexname}{INDEX}
% For TeX, LaTeX, METAFONT, METAPOST, etc. related logos.
% This includes all the logos in the dtk-logos package, see
% http://mirrors.ctan.org/macros/latex/contrib/hologo/hologo.pdf
% plus some extra definitions I made in pa-logos.sty.
\usepackage{pa-logos}
% For typographical conventions stuff including
% \Emph{...}
% \First{...}
% \Keys{...}
% \Literal{...}
% \Menu{...}
% \Place{...}
% \Shell{...}
\usepackage{pa-typographic-conventions}
% For FloatBarrier.
% Put \FloatBarrier to process all unproccesed floats (tables and figures).
\usepackage{placeins}
% The mathtools package
% (see http://mirror.utexas.edu/ctan/macros/latex/required/amsmath/amsmath.pdf)
% loads the amsmath package which defines the
% align
% align*
% alignat
% alignat*
% equation
% equation*
% flalign
% flalign*
% gather
% gather*
% multitaper
% multitaper*
% split
% environments and extends amsmath by defining many other commands.
% See
% https://ctan.org/pkg/amsmath
% for information about amsmath and
% http://ctan.math.washington.edu/tex-archive/macros/latex/contrib/mathtools/mathtools.pdf
% for information about mathtools.
\usepackage{mathtools}
% Follow ISO 80000-2:2019
% o put e, i, and pi in upright font automatically
% o use, for example, "\di x" to get "\,mathrm{d}\/x"
% This loads
% o amsmath.sty (which is already loaded above)
% o mathtools.sty
% o upgreek.sty
% Load the package.
\usepackage{pa-mismath}
% Tell mismath that e, i, j, and pi in upright font automatically.
\enumber
\inumber
\jnumber
\pinumber
% To typeset math italic e, i, j, and pi use
% \mathit e
% \mathit i
% \mathit j
% \itpi
% Define \includemedia.
\usepackage{media9}
% Define ``multicols'' environment environment used in demo-multicols.tex.
% CHANGE NEXT LINE?
\usepackage{multicol}
% For \ditto command.
\usepackage{pa-ditto}
% For \DigitDash---a dash the width of a digit in the current font.
\usepackage{pa-figure-dash}
% For \MyRepeat---????.
\usepackage{pa-repeat}
% For \textcent.
\usepackage{textcomp}
% Needed for chapter "Graphics", section "TikZ and PGF".
\usepackage{tikz}
% Needed for the Feynman diagram in ap-physics.tex.
% Tikz-feynman requires lualatex instead of pdflatex be run.
\usepackage[compat=1.1.0]{tikz-feynman}
% For \verbatiminput.
\usepackage{verbatim}
答案1
$ f^{\prime}(x) $作为后备方案，你可以使用$ f'(x) $。但是，带重音符号的符号应该可以工作，下面介绍如何修复该问题。
就像评论中讨论的那样，如果不知道你那边发生了什么，就很难真正提供帮助。但我最好的猜测是，撇号 ( ') 被修改了某个地方，让引号工作得“更好”，但没有考虑到它在数学模式下的使用。
尝试在您的上方添加以下代码\begin{document}：
\let\oldapo='
\makeatletter
\catcode`\'=\active
\def'{\ifmmode ^\bgroup\expandafter\prim@s\else\expandafter\oldapo\fi}
\makeatother
数学中是否仍缺少素数？如果是，请尝试将此代码移至 之后\begin{document}。
如果不起作用
删除上面提供的代码并将以下内容添加到您的文档中：
\PackageWarning{DEBUG}{Meaning of accent1: (\meaning')}
(Meaning of accent1: (\meaning'))
\catcode`\'=\active
\PackageWarning{DEBUG}{Meaning of accent2: (\meaning')}
(Meaning of accent2: (\meaning'))
\catcode`\'=12
\PackageWarning{DEBUG}{Meaning of accent3: (\meaning')}
(Meaning of accent3: (\meaning'))
这应该会在您的代码中输出一些警告。在我的答案的评论中分享它们，或更新您的原始问题以包含它们。这些信息可以帮助我们了解您那边发生了什么。
如果您找不到警告，这些行也应该作为普通文本打印在您的文档中。复制它，或对其进行截图。
一定要说清楚它是否对你有用！:)