##Graph arrow styles
##arrow styles 
##Use -> => >> > arrow symbols to influence the style of the arrow##rankdir=LR makes the graph be laid out from left to right, instead of the default from up to down.
graph {
    rankdir = LR;
    a b;
    a->c;
    a->e;
    a->b->c=>d<->e
    a<<b;
    c<e;
};