$$\left( {a \vee b} \right) \to \left( {b \wedge c} \right)$$

$$\left( {a \wedge b} \right) \to \left( {b \vee c} \right)$$

$$\left( {a \vee b} \right) \to \left( {b \to c} \right)$$

$$\left( {a \to b} \right) \to \left( {b \to c} \right)$$

9 edges, 6 vertices

6 edges, 4 vertices

10 edges, 5 vertices

9 edges, 5 vertices