What's the reason to name edge like (u, v)? When they are printed letters they seem pretty distinct but with TeX or Latex it's almost impossible to see their difference (especially if you read problem fast). Look, they differ only by one tiny line:
It is really annoying to turn on my brain just to understand this is v or u (or mb v and v, who knows). I think it is especially hard for visually impaired.
Even if there is some "mathematical" idea behind it, just name x and y and all life becomes easier.