${\displaystyle \eta _{1}}$ and ${\displaystyle \eta _{2}}$ are input nodes.

${\displaystyle \eta _{3}}$ conclusion is the clause ${\displaystyle \left\{a,b,c\right\}}$

${\displaystyle \eta _{3}}$ premises are the conclusion of nodes ${\displaystyle \eta _{1}}$ and ${\displaystyle \eta _{2}}$ (its parents)

The DAG would be