r.watershed alorythm

[Brad J Cadle]

Hi there,
        I was just wondering if anyone knew what the general algorythm for
identifying watersheds was in r.watershed.  I would like to know, but would 
rather not spend the time going through all the source code.  I basically
just need to know what criteria the routine uses (based on user input) to 
identify where the basin boundaries are.  (Note: I already realize
that The user sets the minimum basin size as a parameter.  I am more in
terested in how the routine uses this information in conjuction with the 
slopes of the hillsides).

                                                        -Brad