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Fuzzy Database Query Languages and Their Relational Completeness Theorem
February 1993 (vol. 5 no. 1)
pp. 122-125

Two fuzzy database query languages are proposed. They are used to query fuzzy databases that are enhanced from relational databases in such a way that fuzzy sets are allowed in both attribute values and truth values. A fuzzy calculus query language is constructed based on the relational calculus, and a fuzzy algebra query language is also constructed based on the relational algebra. In addition, a fuzzy relational completeness theorem such that the languages have equivalent expressive power is proved.

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Index Terms:
fuzzy database query languages; relational completeness theorem; fuzzy sets; attribute values; truth values; fuzzy calculus query language; relational calculus; fuzzy algebra query language; fuzzy set theory; information retrieval; query languages; relational databases
Y. Takahashi, "Fuzzy Database Query Languages and Their Relational Completeness Theorem," IEEE Transactions on Knowledge and Data Engineering, vol. 5, no. 1, pp. 122-125, Feb. 1993, doi:10.1109/69.204096
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