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Is "$\not\exists$" a logic quantifier? We use it in Math and we are asked to say if it's logic quantifier or not.

(You may not see it properly, but it's the standard existential quantifier "$\exists$" with diagonal from right upper corner to left bottom corner. It should mean that "it does not exist".)

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    $\begingroup$ It is very commonly used as a quantifier. It is a shorthand notation for $\neg \exists$ $\endgroup$ – B.Swan Oct 7 '19 at 18:39
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Yes, it is a quantifier. You can write the equivalence

$$\not\exists a:p(a)\equiv\forall a:\lnot p(a).$$

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  • $\begingroup$ Thx, sir! Is this also a logic quantifier? ∃! $\endgroup$ – naruto25 Oct 7 '19 at 18:42
  • $\begingroup$ @naruto25: yep. And there is no $\forall\not !$. $\endgroup$ – Yves Daoust Oct 7 '19 at 18:47

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