One problem (feature?) of math notation is that paper authors don't follow a consistent convention for symbols, so what you're asking might not even be possible... It doesn't help that different math domains might use different symbols for the same concept! That being said, there is the ISO 80000-2 standard that defines recommendations for many of the math symbols, with mentions of other variations, see https://web.archive.org/web/20210705180417/https://people.en...
You might want to read through that as a starting point.
Unfortunately, just knowing the notation (being able to read the symbols) is not usually enough. Understanding each symbol/concept usually requires knowing the math context and other related definitions of the domain where the notation is used. In other words, knowing the notation is not a shortcut for learning math... But still, I hear you about the need to select some symbols then right-click and choose "read this to me" or "explain this to me."
One thing I love about programmers is that they rarely use complex symbols. They are the complete opposite to mathematicians in this regard. Basically all programming languages consist just of ASCII keywords. So when in doubt about some keyword, you can just use Google and type it in. Together with the name of the language.
I guess symbols look fancier and are more concise.
Also, mathematicians do love their PDFs. No doubt because it supports their beloved symbols so well. Of course PDFs are terrible for the Web and screens in general, but only a programmer would care about that.
Check out this excerpt of definitions of basic math notation I use in my books: https://minireference.com/static/excerpts/set_notation.pdf It has some examples of the "alien symbols" ∀ (for all), ∃ (there exists), etc.
One problem (feature?) of math notation is that paper authors don't follow a consistent convention for symbols, so what you're asking might not even be possible... It doesn't help that different math domains might use different symbols for the same concept! That being said, there is the ISO 80000-2 standard that defines recommendations for many of the math symbols, with mentions of other variations, see https://web.archive.org/web/20210705180417/https://people.en... You might want to read through that as a starting point.
Unfortunately, just knowing the notation (being able to read the symbols) is not usually enough. Understanding each symbol/concept usually requires knowing the math context and other related definitions of the domain where the notation is used. In other words, knowing the notation is not a shortcut for learning math... But still, I hear you about the need to select some symbols then right-click and choose "read this to me" or "explain this to me."