DIVISION (Relational Operation)

The DIVISION operation, identified by $÷$, is the inverse of Cartesian Product (SQL). An intuitive property of the operator is that you can consider that:

$$\begin{array}{rl}U& =R\times S\\ U÷R& =S\\ U÷S& =R\end{array}$$

For a tuple $t$ to appear in the result $T$ of the DIVISION, the values in $t$ must appear in $R$ in combination with every tuple in $S$.