\begin{sequencediagram} \newthread{actor}{Actor}{} \newinst[4]{concordia}{:Concordia}{} \newinst[2]{eth}{:Ethereum}{} \newinst[1]{orbit}{:OrbitDb}{} \begin{call}{actor}{Sign up}{concordia}{Sign up form} \end{call} \begin{call}{actor}{Submit}{concordia}{Personal information form} \begin{call}{concordia}{Create user}{eth}{New user ID} \end{call} \begin{call}{concordia}{Create databases}{orbit}{} \end{call} \end{call} \begin{call}{actor}{Submit}{concordia}{Home page} \begin{call}{concordia}{Save personal information}{orbit}{} \end{call} \end{call} \end{sequencediagram}