Consider the following two relations:

Relation $r$

Relation $s$

give the resulting table of the following relational algebraic expressions. You should specify the schema

as well as the values of all attributes for all tuples in your solutions. If you believe the expression does not

make sense, put $\frac{O}{?}$ as your answer. Write down intermediate results for partial credits.

${}_E>20(s)$

${}_{C,D}(r)$

$pro{d}_{F,D}$ E$>$F $($s$)$

$rS($hint: cross product$)$

${}_{B,C,r.D}(rs)($hint: this is natural join$)$

$rS$

${}_{B,D}(r)[{}_D,F<mn\; id="EditorElement\_3441165">8</mn><mi\; id="EditorElement\_3441169">(</mi><mi\; id="EditorElement\_3441168">s</mi><mi\; id="EditorElement\_3441170">)</mi><mi\; id="EditorElement\_3441173">]</mi>$