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Given $A \subseteq \mathbb{N}, A \neq \emptyset$, prove that A has a minimum element.

Can anyone help me with this problem?

not all wrong
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NightRa
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    Please try to phrase questions a little more politely, rather than as commands :) It helps to keep things friendly if you say "I've tried to solve this problem by [...] but then I got stuck. Can anyone give me a hint?" instead of "Do this." (I've edited it in this direction. If you can show any attempt that's very helpful.) – not all wrong Aug 14 '13 at 23:17

1 Answers1

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Hint Use induction. Assume that $A$ has no least element, and show it must be empty, arriving at a contradiction.

Pedro
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