unicode-math-xetex.sty
在和的开头unicode-math-luatex.sty
,我发现
\RequirePackage{xparse,l3keys2e}
\RequirePackage{fontspec}
\RequirePackage{fix-cm}
\RequirePackage{amsmath}
\cs_set_protected:Npn \__um_after_package:nNn #1 #2 #3
{
\AtBeginDocument
{
\cs_new_protected:Npn #2 {#3}
\@ifpackageloaded {#1} {#2} {}
}
}
\RequirePackage{xparse,l3keys2e}
\RequirePackage{fontspec}
\RequirePackage{fix-cm}
难道这是特殊的招数?