Pumping lemma for Regular Languages (RLs) states that
For any Regular Language (L) there is a number p such that for any string w in L such that length of w,|w|>=p then there is a partition of w = uvy, where |uv|<=p, |v|>0 so that for every i in whole numbers uv^iy will also be in L.
But in the case of pumping lemma for Context-Free Languages (CFLs)
For any CFL (L) there is a number p such that for any string w in L such that length of w,|w|>=p then there is a partition of w = uvxyz such that length of substring |vxy|<=p, |vy|>0 then for every i in whole numbers, uv^ixy^iz will also be in L
My question is in case of RLs we bounded the starting part of string u by saying that |uv|<=p, but we have no bound on u in case of CFLs why?