Consider the E/R diagram above, and suppose that a1 and a2 are entities of entity set A, b1
and b2 are entities of set B, and c1 and c2 are entities of set C. The arrows limit the possible
relationship sets for R and S. Describe the limitations on these relationship sets. Then, confirm
your understanding by identifying which of the following relationships sets for R and S are
possible according to the diagram.
R={(a1,b1),(a2,b2)};S={(b1,c1)}
R={(a1,b1)};S={(b1,c1),(b2,c2)}
R={(a1,b1),(a2,b2)};S={}
R={(a1,b1),(a2,b1)};S={(b1,c2)}
A
B
C
Consider the E/R diagram above, and suppose that a1 and a2 are entities of entity set A,b1
and b2 are entities of set B, and c1 and c2 are entities of set C.The arrows limit the possible
relationship sets for R and S. Describe the limitations on these relationship sets. Then, confirm
your understanding by identifying which of the following relationships sets for R and S are possible according to the diagram.
R ={(a1,b1),(a2,b2)};S={(b1,c1)}
R={(a1,b1)};S={(b1,c1),(b2,c2)}
R={a1,b1),(a2,b2)};S={}
R={(a1,b1), (a2,b1)}; S ={(b1,c2)}