Lecture 15
Section outline
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November 7th, Thursday (08:30-10:30)
Context-free grammars
- Rewrite relation, reflexive and transitive closure
- Derivation, leftmost derivation and rightmost derivation
- Language generated by a CFG
- Sentential forms for a CFG
- Derivation composition
- Derivation factorisation
Exercises
- Write a CFG for the language \( L \) of all strings with balanced parentheses (assume \( \varepsilon \not \in L \))
- Write a CFG for the language \( L = \{ w \; | \; w = a^i b^j c^k, \; i, j, k \geq 1 \} \)
References
- Hopcroft et al., chapter 5