Keyphrases
- tree automata
- xml schema
- regular expressions
- regular tree languages
- context free grammars
- finite automata
- xml documents
- context free
- xml data
- integrity constraints
- tree languages
- pattern matching
- metadata
- data exchange
- relational databases
- object oriented
- conceptual model
- xml queries
- xml databases
- building blocks
- conceptual schemas
- finite state
- query language
- finite automaton
- query evaluation
- semantic information
- data model
- document centric
- information retrieval