 It is important to keep in mind that all the items in the grading system are independent.One can then have grades like "D4 4º VIIc A3 E3", or "D1 7º VIIc (A0/VIIIb) E1".The first route takes a whole day to be climbed, mostly on easy terrain, but with some serious aid and a very hard crux (when compared to the general grade) that cannot be bypassed by aiding.