sverweij/mscgen_js

msc{
    a,b,c,d;
    
    a =>> b [label="start the action!"];
    b >> a [label="will do!"];
    
    b alt d [label="hunky-dory scenario"] {
        b =>> c [label="within b alt d"];
        c =>> d [label="could you help me?"];
        d -> c [label="help"];
        c => c [label="make party"];
        c >> b [label="party started"];
        b >> a [label="party started"];
    };
    
    b -> c;
}