4. Look at the definition of a Boolean algebra. a) How many operations must be defined on the set? b) What properties must each of these operations satisfy? 5. Is the set of non-negative integers {0, 1, 2, 3, ...} under the operations of addition and multiplication a Boolean algebra? Why or why not? 6. Complete each statement (Try not to look at the set identities, and just think logically.) a) B U BC = c) uc = b) C n CC d) U A =