Division Algorithm "help"

[gam3r]

Figured i would get most replies here!
Trying to understand this algorithm:

And i don't understand the solution, i've dry run it a few times but i seem to get stuck. I don't understand where the numbers which the backwards arrow(s) point to in the solution, can anyone help?

Here is the soln.

Cheers

 

[namnoc]

All I can see is that you are defining a function recursively. So if you don't calculate the divide function directly, you can follow the steps till you get to divide (0,x) which always has the answer (0,0). From there you can follow the steps backwards till you get the original answer you wanted.