Create a section/wiki page for unfamiliar or potentially confusing notation

Thank you for putting this together! I've been studying functional programming on and off for years, and this has reinforced some of the concepts I've learned, clarified others, and taught me new ones. Very nice work.

As I was reading, I came across two notation idioms that confused me, that I'm pretty sure have nothing to do with FP:

• The symbol ≍ (which is a black box on my Android, fwiw). From googling, I think it means either logical equivalence, or just equivalence. Not being a mathematician, I'm not sure which it is, and what, specifically, the differences between those are. I can guess why it's preferred over = (which means assignment), but I'm not completely sure why it's different from === (I'm also not a JavaScript expert).
• This pattern: ;[1] I'm guessing it means: here's a plain value? and that it's written that way, because of the linter?

Anyway, these details can confuse, and like I said, they're not about FP, so I was thinking it might be nice to have a section, or a wiki page, for them - almost like the sections at the front of many programming books, where they explain how code sections are formatted, that kind of thing. I'm happy to create a wiki page, but I don't know the explanations for either ≍ or ;[1].

Review the issue's two examples, ≍ and ;[1], and inspect the repository's existing documentation structure before choosing a section or wiki page. Research what each notation means in this JavaScript and functional-programming context. Done means a focused explanatory page or section covers both examples and resolves the stated confusion.