A - 1 - SINGLE
E - 5 - EXTENTION
I - 9 - SELF
O - 15 - CIRCULARITY
U - 21 - OTHER
1+5 = 6 (inverted 9; i inverted => ! (not))
1+5+9 = 15
1+5+15 = 21
9+15+25 = debt (IOU)
1+21 = 22 SINGLE OTHER
5+21 = 26 OTHER EXTENSION
9+21 = 30 SELF & OTHER