Example (Cont.) Some members of D+(cont.): B>H. Apply the coalescence rule(8);B>H/holds. Since HCHI and CG Hand CGHI=,the coalescence rule is satisfied with a being B,B being H,8 being CG,and y being H.We conclude that B H. A>CG. A>CGHI and A>HI. By the difference rule,A> CGHI -HI. Since CGHI -HI=CG.A>CG. Database System Concepts,5th Ed. c.6 ©Silberschat乜，Korth and SudarshanDatabase System Concepts, 5 C.6 ©Silberschatz, Korth and Sudarshan th Ed. Example (Cont.) Some members of D+ (cont.): B H. Apply the coalescence rule (8); B HI holds. Since H  HI and CG H and CG  HI = Ø, the coalescence rule is satisfied with  being B,  being HI,  being CG, and  being H. We conclude that B H. A CG. A CGHI and A HI. By the difference rule, A CGHI – HI. Since CGHI – HI = CG, A CG