As others have mentioned, the Wikipedia article [0] provides a good listing of common symbols. If you are trying to read something that uses symbols not in that

As others have mentioned, the Wikipedia article [0] provides a good listing of common symbols. If you are trying to read something that uses symbols not in that list (or in a way different from that list), you best bet would be to find a textbook on the subject. Most math books have a glossary of symbols at the beginning or end. Also, as long as we are on the topic of bad math notation, I would caution that some sources use the symbols in subtly different ways, so you should be sure to check the paper itself for specific conventions. [0] https://en.wikipedia.org/wiki/List_of_mathematical_symbols https://en.wikipedia.org/wiki/List_of_mathematical_symbols