RE: https://infosec.exchange/@lcamtuf/116084014905792600

Any math-minded people here who can explain WTF these symbols mean? πŸ˜³πŸ˜΅β€πŸ’«

@elin well, ≩ should be pretty obvious.

a quick google finds β‹› and β‹š have opposite meaning; i.e. x β‹› y is equivalent to y β‹š x. this allows you to not specify which one is the larger one, yet still reason with inequalities (for instance, x β‹› y implies -x β‹š -y).

the other ones just seem like notational variants on this.

@deciMae but isn’t ≩ the same as >?

And my brain melts with ⋛… greater than, equal to, or less than… isn’t that just everything? 🀯 I would think x β‹› y is also equivalent to y β‹› x… but then… what is the point?

I think the only thing these symbols prove is that I’m not a mathematician πŸ˜…

@elin it is, yeah, but sometimes it is important to be explicit about it.

and yeah, that is everything, but if you say x β‹› y you mean a particular one, without being particular about which one. like, the example they used on wiktionary is if f is differentiable and concave, if x1 β‹› x2 then f'(x1) β‹š f'(x2). i.e. the relative signs are opposite

so this is used to indicate *relative* signs. i.e. a β‹š b and c β‹› d means sign(a - b) = - sign(c - d).

so to be clear, that means x β‹› y is equivalent to y β‹› x in a vacuum, but if you write these two next to each other there is an implicit sharing of cases, meaning that (x β‹› y and y β‹› x) is equivalent to (x = y)

i do agree that it doesn't seem like it is very useful, and the notation is a bit confusing, but this is what it is defined as

@deciMae thanks! I’m sure I’m going to use it to confuse colleagues 🀭