| Title: | Một vài kết quả liên quan đến bài toán thành viên trong lớp phụ thuộc hàm |
| Authors: | Lê, Đức Minh |
| Keywords: | Toán học;Lớp phụ thuộc hàm |
| Issue Date: | 1996 |
| Publisher: | Đại học Quốc gia Hà Nội |
The main purpose of the paper is to study some problems related to the membership problem in the class of functional dependencies. In the paper a way of proving the equivalence of consequences by Armstrong axiomas and by logical values on the basic of the algorithm for finding the closure of a set of attributes. Such as, for a set F of functional dependencies and a functional dependencies and a functional dependency f then the three followings are equivalent: 1) F implies f by Armstrong axiomas, 2) F implies f by logical values, and 3) F implies f by relations. The paper give a necessary and sufficient condition for testing that whether a relation R satiesfies the set F of functional dependencies or not. The paper also mentions some idea for implementing the algorithm to test deduction of a functional dependency from the given set of functional dependences.
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