Keyphrases
- context free grammars
- context free languages
- syntactic pattern recognition
- grammatical inference
- context free
- visual languages
- grammar induction
- regular expressions
- tree adjoining
- formal languages
- production rules
- covering arrays
- tree automata
- closure properties
- natural language
- lexical semantics
- attribute grammars
- semantic parsing
- xml schema
- regular languages
- expressive power
- information extraction