Exactly. This is a nomenclature issue. When this is spelled out it is easily understood. Math is not the issue here. Should CS students have an intro to abstract algebra? Probably. Do CS students (in those programs where CS isn't conflated with IT) take 3+ years of math courses? Yes.
Anyone who doesn't use that nomenclature on a regular basis is bound to need a refresher legend. The concepts are easily remembered (and used in all kinds of programming). But which direction the e points is less easily remembered.
I learned the details of photosynthesis, the Krebs cycle, and a lot of other basic biochemistry in high school, but I don't remember much of that at all.
I did a fair bit of set work in college, but it took me about a minute to dig some of that up to read and understand the relationship that's being described. I don't think I've worked with sets using actual mathematical notation in over 10 years. It wouldn't have surprised me if I couldn't read it (although I would've found it somewhat distressing).
The weird part is his audience: active students and researchers within the field of CS. They're the ones that I would've expected to be most likely to understand what it said.