TikzCD：一切都混在一起了

Question

當我在兩個箭頭之間有同倫時，事情似乎進展順利：

\documentclass[12pt]{article}
\usepackage{tikz-cd}
\begin{document}
\begin{center}
 \begin{tikzcd} 
A
  \arrow[r, bend left=60, "F" ""{name=a, below}]
  \arrow[r, bend right=60, "G"', ""{name=b}]
 & B
  \arrow[Rightarrow, from=a, to=b, "\Theta"]
 \end{tikzcd}
\end{center}
\end{document}

（缺少的同倫箭頭似乎是我的顯示器中的一個錯誤。它在你的顯示器上應該可以正常工作。）

但是當我嘗試兩個連續的同倫時，一切都混在一起了：

 \documentclass[12pt]{article}
 \usepackage{tikz-cd}
 \begin{document}
 \begin{center}
  \begin{tikzcd}
  A 
   \arrow[r, bend left=90, "F", ""{name=a, below}]
     \arrow[r, "G"', ""{name=b}]
     \arrow[r, bend right=90, "H"' ""{name=c}]
  & B
     \arrow[Rightarrow, from=a, to=b, "\Theta"]
     \arrow[Rightarrow, from=b, to=c, "\Psi"]
  \end{tikzcd}
  \end{center}
  \end{document}

我怎樣才能解決這個問題？謝謝！

Answer 1

 \documentclass[12pt]{article}
\usepackage{tikz-cd}

\begin{document}

 \begin{center}
 \tikzcdset{column sep/normal=3em}
  \begin{tikzcd}
  A
   \arrow[r, bend left=70, "F", ""{name=a, below}]
     \arrow[start anchor={[xshift=3ex]west}, end anchor={[xshift=-3ex]east},r, "G" pos=0.3, ""{name=b},""{name = bb, below}]
     \arrow[r, bend right=70, "H"', ""{name=c}]
  & B
     \arrow[Rightarrow, start anchor={[yshift=-0.75ex]north}, end anchor={[yshift=0.5ex]south}, from=a, to=b, "\Theta" pos = 0.4]
     \arrow[Rightarrow, start anchor={[yshift=-0.75ex]north}, end anchor={[yshift=0.5ex]south}, from=bb, to=c, "\Psi" pos = 0.35]
  \end{tikzcd}
  \end{center}

\end{document}