1. set theoretic definition for languages
- alphabet
- word
- empty string
- language
- empty language
- finite language
- formal grammar
- concatenation
- reversal
- Kleene star
- string homomorphism
1. regular languages
- regular language
- regular grammar
- regular expression
- properties of regular languages
- pumping lemma
- distinguishable strings
- equivalence class of distinguishable strings
- Myhill-Nerode theorem
2. context-free languages
- context-free language
- context-free grammar
- context-free expression
- properties of regular languages
- context-free pumping lemma