How can I evaluate the expression $ (A_1 \cup \ldots \cup A_n) \cap (B_1\cup \ldots \cup B_m) \cap (C_1 \cup \ldots \cup C_o) ?$
I know that for $(A_1 \cup \ldots \cup A_n) \cap B_1$ we get $((A_1\cap B_1) \cup \ldots \cup (A_n\cap B_1))$, but don't knw how the generalize this to the above.