As for (2): It doesn't really make a lot of sense to me to have a place for _expression_ x4 in addition to a place for the function. It's as if "klama" was defined as "x1 goes to x2 ... and has name x6". The place for the range is also redundant. It's as if "jalge" was defined as "x1 is the result of x2 among potential results x3", or something like that. "fancu" ought to have just two places: "x1 is a function of x2".