in q3.c and d, I can find a division, w=uvxyz, where the contradiction of pumping lemma doesn't give us a word, w'=u(v^i)x(y^i)z, which doesn't belong to the language.

i.e. where I need to prove that for all divisions of w, I can find a pumping which w' doesn't belong, I still find a division which keeps w' in the language, though I'm pretty sure that these languages aren't context free.

is pumping lemma the only proof- tool we have ?