Extend the Fraction class by adding methods that conform to the informal protocol NSComparisonMethods, as listed earlier in this chapter. Implement the first six methods from that protocol...

Extend the Fraction class by adding methods that conform to the informal protocol NSComparisonMethods, as listed earlier in this chapter. Implement the first six methods from that protocol (isEqualTo:, isLessThanOrEqualTo:, isLessThan:, isGreaterThanOrEqualTo:, isGreaterThan:, isNotEqualTo:) and test them.