4 is half of 8
4_old is 3_through_4. 3_old is not 3_through_4. 4_old is not 2_through_4. 2_old is not 2_through_4. 3_old is not 2_through_4. 2_old is 2_through_4. 3_old is 3_through_4. 3_old is 2_through_4. 4_old is 2_through_4. 4_old is not 3_through_4.