如何调整暗示符号的符号

Question

我想获得以下暗示箭头：

但根据 percusse 的建议TikZ-cd 中箭头中间的描述不代表左箭头我会得到这个：

如您所见，我想要获取两条平行曲线之间距离较大的蕴涵符号，而不是两条曲线各自的宽度较大的蕴涵符号。 tikz-cd 可以做到这一点吗？

以下是 percusse 的 tex 文件的修改：

\documentclass{article}
\usepackage{tikz-cd}
\usetikzlibrary{decorations.markings}
\tikzset{degil/.style={line width=1.5pt,
        decoration={markings,
        mark= at position 0.5 with {
              \node[transform shape] (tempnode) {$\backslash\backslash$};
              %\draw[thick] (tempnode.north east) -- (tempnode.south west);
              }
          },
          postaction={decorate}
}
}

\tikzset{
commutative diagrams/.cd,
arrow style=tikz,
diagrams={>=open triangle 45, line width=1.5pt}}


\begin{document}

\begin{tikzcd}[arrows=Rightarrow]
\fbox{\parbox{2cm}{$f$ is differentiable at point $P$}}
\arrow[bend right]{rr}{} &\quad    
\qquad&\fbox{\parbox{2cm}{$f$ is continuous at $P$}}\arrow[bend right,degil]{ll}{}
\end{tikzcd}
\end{document}

Answer 1

这里的关键double distance很有用（参见 TikZ 手册，第 161 页）。

\documentclass{article}
\usepackage{tikz-cd}
\usetikzlibrary{arrows}
\usetikzlibrary{decorations.markings}
\tikzset{degil/.style={line width=0.5pt,double distance=5pt,
        decoration={markings,
        mark= at position 0.5 with {
              \node[transform shape] (tempnode) {$\backslash\backslash$};
              %\draw[thick] (tempnode.north east) -- (tempnode.south west);
              }
          },
          postaction={decorate}
}
}

\tikzset{
commutative diagrams/.cd,
arrow style=tikz,
diagrams={>=open triangle 45, line width=0.5pt}}


\begin{document}

\begin{tikzcd}[arrows=Rightarrow]
\fbox{\parbox{2cm}{$f$ is differentiable at point $P$}}
\arrow[bend right,double distance=5pt]{rr}{} &\quad    
\qquad&\fbox{\parbox{2cm}{$f$ is continuous at $P$}}\arrow[bend right,degil]{ll}{}
\end{tikzcd}
\end{document}