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I can rather easily imagine that some mathematician/logician had the idea to symbolize "it E xists" by $\exists$ - a reversed E - and after that some other (imitative) mathematician/logician had the idea to symbolize "for A ll" by $\forall$ - a reversed A. Or vice versa. (Maybe it was one and the same person.)

What is hard (for me) to imagine is, how the one who invented $\forall$ could fail to consider the notations $\vee$ and $\wedge$ such that today $(\forall x \in X) P(x)$ must be spelled out $\bigwedge_{x\in X} P(x)$ instead of $\bigvee_{x\in X}P(x)$? (Or vice versa.)

Since I know that this is not a real question, let me ask it like this: Where can I find more about this observation?

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    One thing is for sure: $\vee$ is for **V** el (= or). $\wedge$ *could* be for **A** nd.2011-08-26
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    One *big* thing in favour of $\forall$ and $\exists$: The typesetter you went to could be counted on to have "A" and "E" in a sans-serif font and turning a single letter 180 degrees is trivial. Mathematical typesetting didn't develop in a vacuum - you had to pay more to get pages with lots of math in it typeset, so it was only with the advent of TeX that we could get virtually any symbol in our printed output.2011-08-26
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    @kahen: Good answer! (Maybe it was not a logician who had the idea but his typesetter?) With $\vee$ also $\wedge$ was available at those times, and from those two signs the quantifier signs could/should have been derived.2011-08-26
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    The title and body don't seem to match. Which question are you more interested in?2011-08-27

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