Problem 1 (Good Variable Ordering in BDD). In class we learnt that choosing a good variable ordering affect the BDD construction greatly. In this problems we will work on choosing good variable ordering for BDD construction. For the following functions find out a good variable ordering and draw the ROBDD. 1. F(a, b, c, d) = abc + b'd + c'd. 2. G(a, b, c, d, e) = (a + be)(d + c)