[stchacademy]

Thanks a lot for your kind words. I really appreciate it! :)

Regarding "?"-functions.

Yes, the idea was this: to separate "normal" functions (that is, functions returning something or altering a value in-place) from functions returning a boolean values - let's call them predicates. That's not a rule, it's merely by convention (at least in the built-in library).

Re: "if" vs "if?", as I said before... the second one is a predicate, meaning: it does return a boolean value (that of the passed condition parameter). And the main use is... chaining with an "else". ;-)