pushdown automata (pda)

Deterministic cfgA language L is said to be a deterministic context-freelanguage if there exists a dpda M such that L = L(M).For example, {a n b n : n ≥ 0} is a deterministic cfg.The other familiar example {ww R : w ∈ Σ ∗ } is known tobe non-deterministic.A context-free language L can be shown, indirectly, tobe non-deterministic by assuming it to be deterministicand reaching a contradiction.Pushdown Automata – p. 19