# database

posted by
**SUE** on
.

Prove that for any relation R(X,Y)

Select Select(R (X=x0) (Y=y0))) =

Select (R(X=x0) and Y=y0))

What is an equivalent form of (Select(R (X=x0) or (Y=y0)))?

posted by
**SUE** on
.

Prove that for any relation R(X,Y)

Select Select(R (X=x0) (Y=y0))) =

Select (R(X=x0) and Y=y0))

What is an equivalent form of (Select(R (X=x0) or (Y=y0)))?