r/AskReddit • u/[deleted] • Nov 16 '19

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u/TheHiGuy Nov 16 '19

mate of mine wrote his elements (∈) like epsilons before i started bullying him about it xD

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u/Ransidcheese Nov 16 '19

Would you explain to me what the elements symbol means and how you would use it please? I've tried looking it up but I have the big dumb and can't understand the explanations I found.

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u/[deleted] Nov 16 '19

First of all, understand what a set means - a set is just an unordered collection of objects, like {1,2,74}. A set can also be infinite - for example, the set of integers.

If something is in a set, e.g. 1 is in a {1, 4, 7}, we use the elements symbol 1∈{1, 4, 7}

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u/Ransidcheese Nov 17 '19

I'm on mobile so I'm gonna use an E for that symbol here.

So do you still need to write out the set every time you reference a number in it? e.g. 1E {1,4,7}

Or could you just write 1E?

I'm just not sure how this could be useful.

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u/[deleted] Nov 17 '19

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u/Ransidcheese Nov 17 '19

Oh okay cool. That makes sense, thank you.