digraph g {
    Start [shape=box];
	s1 [label="x = x_in"];
	s0 [label="y = y_in"];
	s2 [label="while (x > y)"];
	s3 [label="x = x + 1"];
	s4 [label="print(x)"];
	s5 [label="x_out = x"];
	// Rank
	{ rank=same; s0; s1; s5; }
	{ rank=same; s2; s4; }
	{ rank=min; Start; }
	s0 -> s2 [style=invis];
	// Control
	{
		edge [style = bold];
		Start -> {s0 s1 s2 s4 s5};
		s2 -> s3;
	}
	// Data
	{
		edge [color = red];
		edge [constraint = false];
		{s1 s3} -> {s2 s3 s4 s5};
		s0 -> s2;
	}
}