set-intersection

Let R and S be two relations with the following schema R ( P , Q , R1, R2, R3) S ( P , Q , S1, S2) Where {P, Q} is the key for both schemas. Which of the following queries are equi...

Let E, F and G be finite sets. Let $$X = \,\left( {E\, \cap \,F\,} \right)\, - \,\left( {F\, \cap \,G\,} \right)$$ and $$Y = \,\left( {E\, - \left( {E\, \cap \,G} \right)} \right)\...

Let R and S be any two equivalence relations on a non-emply set A. Which one of the following statements is TRUE?

Give a relational algebra expression using only the minimum number of operators from $$\left( { \cup ,\, - } \right)$$ which is equivalent to $$R \cap S$$.