X = 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
Y = 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15
X ↔ Y

Ext-GCD(8, 14) → Twos = 1 → Ext-GCD(4, 7) :

i GCD Bezout AOdd : AEven :
A B ax ay bx by |A-B| A↔B Sx Sy ax
Sx'
ay
Sy'
A
A/2
ax
ax + Y
ay
ay + X
ax
ax/2
ay
ay/2
0 4 7 1 0 0 1
1 4 7 1 0 0 1 3 2 8 4 4 2
2 2 7 4 2 0 1 5 1 Even Even 2 1
3 1 7 2 1 0 1 6 1 2 2 2 2 3 Even Even 1 1
4 3 1 1 1 2 1 2 0 3 2 3 2 1 10 6 5 3
5 1 1 5 3 2 1 0
6 1 1 5 3 2 1 0
7 1 1 2 1 5 3 0
(2)(8) - (1)(14) = 2