Consider the following relations P(X,Y,Z), Q(X,Y,T) and R(Y,V). How many…

Consider the following relations P(X,Y,Z), Q(X,Y,T) and R(Y,V).

How many tuples will be returned by the following relational algebra query?

$\Pi_x (\sigma_{(P.Y=R.Y \wedge R.V=V2))} (P \times R)) – \Pi_x (\sigma_{(Q.Y = R.Y \wedge Q.T>2))} (Q \times R))$

Answer: ___________.