方程组左对齐，并在方程组之间留有额外的垂直空间

Question

我正在尝试获得这样的东西

\documentclass[11pt,a4paper,oneside]{report} 
\usepackage[pdftex]{graphicx}
\usepackage[T1]{fontenc} 
\usepackage{fouriernc}
\usepackage{mathtools}
\usepackage{amsfonts,amsmath,amssymb,amsthm}
\usepackage[a4paper, hmargin={3.5cm,3cm}, vmargin={2.5cm,2.5cm}]{geometry} % margin
\usepackage{multicol}
\usepackage[pdftex]{hyperref}
\DeclareMathOperator{\order}{\mathcal{O}_{K}}
\begin{document} 
\begin{align}
\phi_{\mathcal{C}\Phi} \colon \mathcal{C} &\longrightarrow \Phi \\
 \order & \longmapsto F(x,y)\\
\phi_{\Phi \mathcal{C}} \colon \Phi  &\longrightarrow \mathcal{C} \\
 F(x,y) & \longmapsto \order
 \end{align}
 \end{document}

但这两个函数之间有一个额外的空格，并且只有两个数字，就像这里

\documentclass[11pt,a4paper,oneside]{report} % KOMA-Script book
\usepackage[pdftex]{graphicx} % to work PDFLaTex
\usepackage[T1]{fontenc} 
\usepackage{fouriernc}
\usepackage{mathtools}
\usepackage{amsfonts,amsmath,amssymb,amsthm}
\usepackage[a4paper, hmargin={3.5cm,3cm}, vmargin={2.5cm,2.5cm}]{geometry} % margin
\usepackage{multicol}
\usepackage[pdftex]{hyperref}
\DeclareMathOperator{\order}{\mathcal{O}_{K}} 
\begin{document}

\begin{gather}
\begin{aligned}
\phi_{\mathcal{C}\Phi} \colon \mathcal{C} &\longrightarrow \Phi\\
\order & \longmapsto F(x,y)
\end{aligned}
\\
\intertext{}
\begin{aligned}
\phi_{\Phi \mathcal{C}}\colon \Phi &\longrightarrow \mathcal{C}\\
   F(x,y) & \longmapsto \order
\end{aligned}
\end{gather}
\end{document}

在这个版本中，我得到了我想要的编号+额外的空间，但我无法修复箭头对齐和功能对齐。

任何帮助都值得感激。谢谢。

Answer 1

您可以使用split获取方程编号和\\[2ex]额外的空间

\documentclass[11pt,a4paper,oneside]{report}
\usepackage{graphicx}   %% no need of pdftex
\usepackage[T1]{fontenc}
\usepackage{fouriernc}
\usepackage{mathtools}
\usepackage{amsfonts,amssymb,amsthm}  %% no need of amsmath, already loaded by mathtools
\usepackage[a4paper, hmargin={3.5cm,3cm}, vmargin={2.5cm,2.5cm}]{geometry} % margin
\usepackage{multicol}
\usepackage{hyperref}   %% no need of pdftex
\DeclareMathOperator{\order}{\mathcal{O}_{K}}
\begin{document}
\begin{align}
\begin{split}     %%<------------------------
\phi_{\mathcal{C}Φ} \colon \mathcal{C} &\longrightarrow Φ\\
 \order & \longmapsto F(x,y)
  \end{split}\\[2ex]         %%%<----------- here  adjust 2ex accordingly
  \begin{split}     %%<------------------------
\phi_{Φ\mathcal{C}} \colon Φ &\longrightarrow \mathcal{C} \\
 F(x,y) & \longmapsto \order
 \end{split}
 \end{align}
 \end{document}