ProfitRUS wants to become a market leader in the real estate industry through the introduction of onlibne classified advertising service for real estate stakeolders. the object of the project is to provide ProfitRUS with an application which will provide some unique featuresnot available in the other online real estate advertising services. the software should provide an inexpensive way for tenants to look for a property, or for sellers and lessors to list thier property. the application should enhance quicker communications between parties and target a large audience throughout the whole country.

a. what is the requirement specification

b. what is the domain model

c. using of case diagram