LIFER/LADDER

LIFER/LADDER was one of the first database natural language processing systems. It was designed as a natural language interface to a database of information about US Navy ships. This system, as described in a paper by Hendrix (1978), used a semantic grammar to parse questions and query a distributed database.

The LIFER/LADDER system could only support simple one-table queries or multiple table queries with easy join conditions.[1]

Some examples of queries it could accept:

References

  1. ↑ NATURAL LANGUAGE QUERY PROCESSING USING SEMANTIC GRAMMAR