Which language is context-free but not deterministic context-free?
Without a middle marker, a PDA must nondeterministically guess the midpoint of an even palindrome.
Which statements about the CFL pumping lemma are correct?
The lemma guarantees existence of one suitable decomposition, not that every decomposition works.
Which operation preserves context-freeness?
CFLs are closed under homomorphism.
In the CFL pumping lemma, what is the minimum allowed value of the pumping index i?
The lemma requires the pumped string to remain in the language for all integers i >= 0.
Which of these languages is deterministic context-free?
A DPDA can compare a and b using the stack and then read c's.