Fuzzy database query languages and their relational completeness theorem

Y. Takahashi
1993 IEEE Transactions on Knowledge and Data Engineering  
Two fuzzy database query languages are proposed. They are used to query to fuzzy databases that are enhanced from relational databases in 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, this paper proves a fuzzy relational completeness theorem such that both the languages have equivalent
more » ... xpressive power to each other. Index Terms-Fuzzy database, query languages, relational algebra, relational calculus, relational completeness.
doi:10.1109/69.204096 fatcat:ymk7eyqfrrasvddy7jiwoctyba