ftlen(x) (init-rate args only)
int(x) (init- or control-rate args only)
frac(x) " "
dbamp(x) " "
i(x) (control-rate arg; only)
abs(x) (no rate restriction)
exp(x) " "
log(x) " "
sqrt(x) " "
sin(x) " "
cos(x) " "
ampdb(x) " "