EQUIVALENCE OF FUNCTIONAL DEPENDENCIES

You will be given a relation (R) with different functional dependency sets X,Y of that relation , you need to check whether one functional dependency is a subset of other (X⊇Y/ Y"⊇"X ) or both are equal (X=Y). 

Consider X and Y are two FD sets for a relation R , 

1)If all FDs of X can be determined from FDs that are present in Y, we can conclude that Y  ⊇  X    or X⊆ Y    (Y covers X)  . 

2)If all FDs of Y can be determined from FDs that are present in X, we can conclude       X ⊇ Y  or Y⊆ X (X covers Y).

3)If 1 and 2 are satisfied then ,we can say X=Y  or X and Y are equivalent .