(20 points) A propositional formula F is said to be in Conjunctive Normal Form (CNF) if F is a conjunction of clauses C1,C2,, where each clause Ci is a disjunction of literals, and each literal is a symbol representing a proposition or its negation. For example, the following formulas are in CNF: (pq)(rs) pq But, the following formulas are not in CNF: (pq)r pq Convert " (pq)r " into an equivalent formula that is in CNF. Justify your