Functional dependencies with null values, fuzzy values, and crisp values

@article{Liao1999FunctionalDW,
  title={Functional dependencies with null values, fuzzy values, and crisp values},
  author={Stephen Shaoyi Liao and Huaiqing Wang and Weiyi Liu},
  journal={IEEE Trans. Fuzzy Systems},
  year={1999},
  volume={7},
  pages={97-103}
}
This correspondence discusses the functional dependency with null values, fuzzy values, and crisp values. Based on the concepts of the semantic proximity, we present a definition of the fuzzy functional dependency. We show that the inference rules for fuzzy functional dependencies, which are the same as Armstrong’s Axioms for the crisp case, are correct and complete. We also show that dependent constraints with null values constitute a lattice. Functional dependencies in classical relational… CONTINUE READING
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