math771
Jul16-11, 01:55 PM
Consider the set A_n=\{0.9, 0.99, 0.999,...\} , where the greatest element of A_n has n 9s in its decimal expansion. Then 0.999\ldots=1\in\bigcap_{n=1}^\infty{A_n}. Is this possible even though \not\exists{n}(1\in{A_n})?
Edit: I see that 0.999\ldots=1\not\in\bigcap_{n=1}^\infty{A_n}. Sorry :(.
Edit: I see that 0.999\ldots=1\not\in\bigcap_{n=1}^\infty{A_n}. Sorry :(.