## Quick Guide

```
digraph finite_state_machine {
    rankdir=LR;
    size="8,5"

    node [shape = circle ]; q0, q1, q2
    node [shape = doublecircle]; q3

    node [shape = point ]; qi

    qi -> q0;
    q0 -> q0 [ label = "0, 1" ];
    q0 -> q1 [ label = "1" ];
    q1:n -> q2 [ label = "0" ];
    q1:s -> q2 [ label = "ε" ];
    q2 -> q3 [ label = "1" ];
    q3 -> q3 [ label = "0, 1" ];
}
```

**Command:**

```bash
dot -Tpng in.gv -o out.png
```

Reference links:

- https://martin-thoma.com/how-to-draw-a-finite-state-machine/
- https://tex.stackexchange.com/questions/472487/moving-arrow-to-the-bottom-of-the-graph-using-graphviz

## Force Positions

```gv
digraph finite_state_machine {
    rankdir=LR;
    size="10,6"

    node [shape = circle pos="0,3!" label="{phi}"]; q0
    node [shape = circle pos="2,3!" label="{1}"]; q1
    node [shape = circle pos="4,3!" label="{2}"]; q2
    node [shape = circle pos="6,3!" label="{1,2}"]; q3
    node [shape = circle pos="0,0.9!" label="{3}"]; q4
    node [shape = circle pos="2,1!" label="{1,3}"]; q5
    node [shape = circle pos="4,0.9!" label="{2,3}"]; q6
    node [shape = circle pos="6,1!" label="{1,2,3}"]; q7

    node [shape = point pos="1.5,1.5!"]; qi

    qi -> q5;

    q0:nw -> q0 [ label="a, b" ];
    q1 -> q0 [ label="a" ];
    q1 -> q2 [ label="b" ];
    q2 -> q4 [ label="b" ];
    q2 -> q6 [ label="a" ];
    q3 -> q6 [ label="a, b" ];
    q4 -> q0 [ label="b" ];
    q4 -> q5 [ label="a" ];
    q5 -> q2 [ label="b" ];
    q5:e -> q5:e [ label="a" ];
    q6:s -> q4:s [ label="b" ];
    q6 -> q7 [ label="a" ];
    q7:sw -> q6 [ label="b" ];
    q7:n -> q7 [ label="a" ];
}
```

**Command:**

```bash
dot -Kfdp -Tpng in.gv -o out.png
```

**Reference Links:**

https://stackoverflow.com/questions/5343899/how-to-force-node-position-x-and-y-in-graphviz

https://graphviz.org/docs/nodes/