Since everybody likes at least something, there is no one who likes nothing. The statement: "Everyone who likes nothing is also a man" is true because the "Everyone who likes nothing" part results in 0 people. And it's true to say that everyone in a group of 0 people is a man. It's also true that everyone in a group of 0 people is not a man.

But other than vacuous truths, no sentence stating "Only man like XYZ" is true.

[–] TheNamlessGuy@lemmy.world 2 points 1 day ago (1 children)

To be fair, by that logic "Only women like nothing" is also true

[–] yetAnotherUser@discuss.tchncs.de 2 points 1 day ago

It is!

That's the fun thing about vacous truths: They allow both a statement and its inverse to be true.

[–] ch00f@lemmy.world 8 points 2 days ago (1 children)

But only men like set theory, so…

[–] yetAnotherUser@discuss.tchncs.de 4 points 2 days ago

This woman likes set theory because she was involved in a set theory workshop:

https://dmg.tuwien.ac.at/sandramueller/conferences/

But you're kind of right that it's not great that math is still a strongly male dominated field. There is not a single woman's name in the Wikipedia article for set theory, where I first tried to find a counterexample.

Also, you don't necessarily need set theory to arrive at vacuous truths. Logic is enough:

FALSE => [statement]

Still, I think vacuous truths are fun because they are meaningless. Especially because they have to be considered in math or else your carefully constructed proof becomes invalid.

[–] randint@lemmy.frozeninferno.xyz 3 points 2 days ago

I have no idea why you're being downvoted. Perhaps it's coming off as a bit rude to some?