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On Armstrong Relations for Strong Dependencies
Vu Duc Thi - Nguyen Hoang Son
dkovach@aix.swu.bg and dkovach@abv.bg
Abstract:
The strong dependency has been introduced and axiomatized in [2], [3], [4], [5]. The aim of this paper is to investigate on Armstrong relations for strong dependencies. We give a necessary and sufficient condition for an abitrary relation to be Armstrong relation of a given strong scheme. We also give an effective algorithm finding a relation such that is Armstrong relation of a given strong scheme (i.e. , where is a full family of strong dependencies of , and is a set of all strong dependencies that can be derived from by the system of axioms). We estimate this algorithm. We show that the time complexity of this algorithm is polynomial in and .Footnotes
... Thi Institute of Information Technology, Vietnamese Academy of Science and Technology, 18 Hoang Quoc Viet, Hanoi, Vietnam
... Son Department of Mathematics, College of Sciences, Hue University, Vietnam