One thing I've always wanted is a comprehensive guide to mathematical notation, which tells you what symbols mean or at least what field of mathematics they come from. I frequently come across all sorts of weird mathematical symbols in papers, and of course these symbols are virtually never explained, so I have no idea what they mean. Even better would be if there was some way an LLM could read through a paper itself…
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."