答案1
如果你愿意使用 LuaLaTeX:
\documentclass[a4paper,10pt]{scrartcl}
\usepackage[leqno]{mathtools}
\usepackage{unicode-math}
\makeatletter
\renewcommand{\xmapsto}[2][]{\mathrel{\mathpalette\xmapsto@{{#1}{#2}}}}
\newcommand{\xmapsto@}[2]{\xmapsto@@{#1}#2}
\newcommand{\xmapsto@@}[3]{%
\begingroup
\sbox\z@{$\m@th#1\mathop{}\limits_{\;#2\;}^{\;#3\;}$}%
\mathop{\Uhextensible width \wd\z@ 0 "27FC}_{#2}^{#3}%
\endgroup
}
\makeatother
\begin{document}
\begin{gather*}
F\colon\mathbb{K}^n \xmapsto{A} \mathbb{K}^m \\
A \xmapsto[aaaaa]{bbbbbbbbbb} B
\end{gather*}
\end{document}
另一方面,\mapsto
通常不用于表示具有定义域和陪域的映射,而是用于表示其对元素的作用。
答案2
所以这对我来说是可行的:
\documentclass[a4paper,10pt]{scrartcl}
\usepackage{unicode-math}
\usepackage[leqno]{mathtools}
\DeclareSymbolFont{pazosymbols}{OMS}{zplm}{m}{n}
\makeatletter
\ExplSyntaxOn %define \xmapsto
\DeclareMathSymbol \c_pazo_minus \mathbin { pazosymbols } 0
\DeclareMathSymbol \c_pazo_mapstochar \mathrel { pazosymbols } { "37 }
\DeclareMathSymbol \c_pazo_rightarrow \mathrel { pazosymbols } { "21 }
\cs_new_protected_nopar:Nn \pazo_relbar: {
\mathrel {
\mathpalette \mathsm@sh \c_pazo_minus
}
}
\cs_set_protected_nopar:Nn \MT_mapsto_fill: {
\arrowfill@ { \c_pazo_mapstochar \pazo_relbar: } \pazo_relbar: \c_pazo_rightarrow
}
\ExplSyntaxOff
\makeatother
\begin{document}
\begin{align*}
F:\;\mathbb{K}^n \xmapsto{A} \mathbb{K}^m
\end{align*}
\end{document}