19) Consider the universal relation R={X,Y,Z,L,M,N,O,P,Q} and the set of functional dependencies F={{Y,Z}{L},{Y{X},{Z}{M,N},{X}{O,P},{N){Q}}. The primary key is {Y,Z}, Decompose R into second normal form (2NF) and then 3NF relations and specify their keys. [5 points]