
6.8.1 Set theory
Problem:
Prove the identity using the mutual inclusion method and Euler-Venn diagrams.
\[
\begin{array}{l}
A \cup(B \cap C)=(A \cup B) \cap(A \cup C), \\
(A \cup B) \cdot C=(A \cdot C) \cup(B \cdot C) .
\end{array}
\]