In Graphviz, how do I add a shape in the middle of an edge?

Question

I have annotated the following drawing with red to illustrate the effect I'm trying to achieve:

Any idea on how I can achieve this in Graphviz?

Answer 1

You can imitate this behavior by finding a suitable unicode symbol, for example, ⋃ in your case, and putting it into the right position using headlabel attribute:

digraph {
    edge [arrowhead=none]
    Student [shape=rect]
    Faculty [shape=rect]
    o
    Player [shape=rect]

    Student -> o
    Faculty -> o
    o -> Player [
        headlabel="⋃"
        fontsize="25"
        labeldistance="1.7"
        labelangle=0
    ]
}

Result: