begin{forest}
for tree={l+=0.5cm, s sep+=1cm}
[$q_5$ [$q_8$ [$q_1$ [$overline q_2$] [$overline q_6$]]
[$q_9$ [$q_3$ [$vdots$] [$vdots$]] [$q_5$ [$vdots$, tria] [$vdots$]] ] ]
[$q_3$ [$overline q_2$] [$q_4$ [$overline q_2$] [$overline q_6$]] ]
]
end{forest}