I have an engineers understanding of higher maths - overly general and very patchy. Short of taking an undergraduate math course, are there any resources to help me parse math notation? For example, while brushing up on endogeneity/exogeneity, E[B'|X] = 0 completely threw me - I had to search Google for the use cases of a bar/pipe aka latex vert/mid. I usually lose interest in a paper if I get stuck trying to decode the syntax.