\item \points{3} Construct a reduced ordered binary decision diagram (ROBDD) for the formula

  $$(a \lor \neg b) \land \neg(c \lor d) \lor (a \land b),$$

using \textit{variable order} $a < b < c < d$. Use complemented edges and a node for \texttt{true} as the only constant node. To simplify drawing, you may assume that \textit{dangling edges} point to the constant node. Write down all cofactors that you compute to obtain the final result and mark them in the graph.
