 0), and the bucket needs to have its contents split using keys 1 + 1 = 2 bits in length; in general, for any local depth d where d is less than D, the global depth, then d must be incremented after a bucket split, and the new d used as the number of bits of each entry's key to redistribute the entries of the former bucket into the new buckets.Now, 
is tried again, with 2 bits 01.., and now key 01 points to a new bucket but there is still in it (formula_5 and also begins with 01).If had been 000110, with key 00, there would have been no problem, because would have remained in the new bucket A' and bucket D would have been empty.