[beagle3]

I've taken years of English Studies in school, then German, Greek, Russian. That's all useless if I want to read a French book, because they are using a language common in THAT country, and it has nothing to do with the language in another country.

That's not a direct equivalent, but it is close; somewhat equivalent but distinct notations arise in Math and Physics because authors weren't working together (much like natural languages). But otherwise it is "turtles all the way down" - it can only be "simple" or "needlessly complicated" if you assume something about the reader's knowledge.

All of

    integrate(f(x)dx,dx)
    sum f(x_i) for i=1..n
    f(x_1) + f(x_2) + .... + f(x_3)

Are essentially equivalent to a mathematician, often with a preference for the first, whereas someone unfamiliar may claim that only the 3rd is clear and the others are unreadable. A friend of mine was in a classroom where the lecturer started with the first form, when to the 2nd and 3rd over class objections, and finally switching to something like "our function result at the first data point, added to our function result at the second data point, ....". This was an OR class for students pursuing an MBA.