If A and B are subsets of the universal set U, then slow that
(i) `A sub A uu B` , (ii) `A sub B hArr A uu B = B`
(iii) `(A nn B) sub A`

Explanation

To solve the problem, we need to prove three statements regarding the sets A and B, which are subsets of a universal set U. Let's go through each statement step by step.

### Given:
- Let \( U \) be the universal set.
- Let \( A \) and \( B \) be subsets of \( U \).

### (i) Prove that \( A \subseteq A \cup B \)

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