multiplicative setMultiplicativeSet2001-10-19 12:57:282002-03-01 20:30:11Definitionmultiplicative subset\usepackage{amssymb}
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\usepackage{xypic}Let $A$ be a set on which a multiplication operation $\cdot: A \times A \longrightarrow A$ has been defined. A {\em multiplicative subset} of $A$ is a subset $S \subset A$ with the property that $s \cdot t \in S$ for every $s,t \in S$.