I made this diagram and the only thing I want are two parallel arrows that go from node A to B and vice versa by using pb-diagram package, so that I can label both arrows differently, because both nodes interact.

enter image description here

  • Welcome to TeX.SE! Please post the code that generates the graph that you show. This will make it a lot easier to help you. Just add the code (from \documentclass to \end{document}) to you posting.
    – gernot
    Mar 5 '17 at 10:21

A possibile solution using tikz-cd.

enter image description here

     \node[draw,circle,inner sep=.5pt] {#1};

\begin{tikzcd}[row sep=4cm, column sep=2cm]
& \circlett{A} \arrow[ld,Leftrightarrow, "\mathrm{A-B}", "\mathrm{B-A}"'] & \\
\circlett{B}\arrow[rr,leftrightarrow, "\mathrm{B-C}", "\mathrm{C-B}"'] & & \circlett{C} \arrow[lu,Leftrightarrow, "\mathrm{C-A}", "\mathrm{A-C}"']


Not the answer you're looking for? Browse other questions tagged or ask your own question.