For any sets `A ,B ,C ,D` prove that: `(AxxB)nn(CxxD)=(AnnC)xx(BnnD)`

Explanation

To prove that \((A \times B) \cap (C \times D) = (A \cap C) \times (B \cap D)\), we will show that each side of the equation is a subset of the other.

### Step 1: Show that \((A \times B) \cap (C \times D) \subseteq (A \cap C) \times (B \cap D)\)

Let \((x, y) \in (A \times B) \cap (C \times D)\).

**Hint:** Remember that for an element to be in the intersection, it must belong to both sets.

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