词汇表包无法与 amsmath 配合使用

Question

我有一个大学为论文写作提供的自定义文档类。一切都编译得很好，直到我添加了词汇表包。

! LaTeX Error: Command \dfrac already defined.
               Or name \end... illegal, see p.192 of the manual.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.214 \newcommand{\dfrac}{\genfrac{}{}{}0}

结果是

amsmath.sty
214
LaTeX Error: Command \dfrac already defined.
               Or name \end... illegal, see p.192 of the manual.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              
                                                  
l.214 \newcommand{\dfrac}{\genfrac{}{}{}0}

etoolbox.sty

Package etoolbox Warning: Patching '\end' failed! '\AfterEndEnvironment' will not work.

出现错误。我找不到任何解决方案，想知道是否有修复方法？