Give ER diagram and entity type that correspond to this relational representation. Your ER model should include just four entity types, namely, Staff, CompanyProject, Machine and MachineTraining. The information as below.

model Engineering Company domains StaffNumbers = {S0001...S9999} Projectlds = {P0001...P9999) Machinelds = {M000...M999} Names = String Descriptions = String Grades = {1...5) Dates = standard dates relation Staff StaffNo: StaffNumbers Name: Names Grade: Grades AppointmentDate: Dates primary key StaffNo relation Company Project Projectld: Projectlds StartDate: Dates Estimated FinishDate: Dates Manager: StaffNumbers primary key Projectld alternate key Manager foreign key Manager references Staff constraint ((project Company Project over Projectld) difference (project WorksOn over Projectld)) is empty constraint ((project Company Project over Projectld) difference (project Machine over Projectld)) is empty relation Works On Projectld: Projectlds StaffNo: StaffNumbers primary key (Projectid, StaffNo) foreign key Projectld references Company Project foreign key StaffNo references Staff relation Machine Machineld: Machinelds Description: Descriptions DateOfLastService: Dates Projectld: Projectlds primary key Machineld foreign key Projectld references Company Project relation Machine Training Machineld: Machinelds StaffNo: StaffNumbers Date Of Training: Dates primary key (Machineld, StaffNo) foreign key Machineld references Machine foreign key StaffNo references Staff