No, I don’t think APL is a good mathematical notation. For starters, symbols having different meanings depending on whether they are dyadic or monadic is fairly

No, I don’t think APL is a good mathematical notation. For starters, symbols having different meanings depending on whether they are dyadic or monadic is fairly confusing. That’s made worse by the lack of clear delimitations of arguments of functions. The use of prefix notation is also a bad choice because it doesn’t match the way we talk about a lot of operators. Symbols are overused even more than in mathematics (for example, why use a symbol instead of “log”?). There’s also a lot of symbols that are very similar, differing in small ways even though their meaning is fairly different. Yes, mathematical notation is terse (mostly to make manipulations and computations easier to type) but people take special care to avoid ambiguity or too much context dependency, and also don’t try to introduce symbols for everything.