Peter Linz Edition 5 Exercise 8.1 Question 7(f) (Page No. 212)

Question

Show that the following languages on $\Sigma = \{a,b,c\}$ are not context-free. $$L = \{w:n_a(w) <n_b(w)<n_c(w)\}$$.

Comments

in a pda one can't do more than 1 different infinite comparison..

like here

na(w)<nb(w)<nc(w)

3 different infinite comparison...

at most you can do 1 with anyk of pda

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That's not a formal proof.