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I know that the symbol $$ \in $$ stands for membership, but what does the symbol $$ \ni $$ stand for?

Because I know that in the set membership, one symbol stands for subset and the other ones for superset, but I cannot find the meaning of the other symbol


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It's just set membership written the other way round: $x \in X$ and $X \ni x$ mean the same thing. – Johannes Kloos Jan 29 '13 at 14:00
Similar looking symbols are also used by some authors for "such that" - see this question. – Math Gems Jan 29 '13 at 14:36
up vote 1 down vote accepted

Sometimes you want to write the set before the element. $A \ni x$ means exactly the same as $x \in A$.

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Because $a < b$ means the same thing as $b > a$ and $A \subset B$ means the same thing as $B \supset A$, one should not use the mirror image of $\in$ to mean "such that". It is a bad, confusing notation.

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