Q$3.$

$($a$)(4\%)$ What is Deletion Anomaly? Illustrate with an example.

$($b$)(2\%)$ Prove that X $->$ A$,$ if A is a subset of X$,$ according to the definition of functional dependency.

$($c$)(4\%)$ Give an example of a functional dependency X $->$ Y in a relation R where X is not a superkey

in R$.$ Give an example of a non functional dependency where X cannot decide Y$.$