Finite set of integers closed under addition

Can any finite set of integers be closed under addition? Prove your answer.

I kind of have an understanding of what this means but don't know how to prove this?

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Originally Posted by acevipa

Can any finite set of integers be closed under addition? Prove your answer.

I kind of have an understanding of what this means but don't know how to prove this?

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{0}

Hello, acevipa!

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Can any finite set of integers be closed under addition? Prove your answer.

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Suppose the set is: . . . . in increasing order.

. .

. .

The set is not closed under addition.


The only such set is a trivial one: .

Edit: too slow . . . again !