3. Consider the following 2-CNF formula: F = (-a V b)^(-bVc) ^ (cV b) ^ (bV-d) ^ (e Vb) ^ (Ve) • 3a. Draw the digraph corresponding to F. •3b. Use the digraph to prove that F is satisfiable, and find a satisfying assignment to F. • 3c. Further use the digraph to list all satisfying assignments to F.