1
$\begingroup$

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

Thanks

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

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

$\endgroup$
1
$\begingroup$

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.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.