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Inference Rules

20 October, 2015 - 09:21

Armstrong’s axioms are a set of axioms (or, more precisely, inference rules) used to infer all the functional dependencies on a relational database. They were developed by William W. Armstrong.

Let R(U) be a relation scheme over the set of attributes U. We will use the letters X, Y, Z to represent any subset of and, for short, the union of two sets of attributes and by instead of the usual X U Y.

Source: http://en.wikipedia.org/wiki/Armstrong%27s_axioms