Elementary Factors and Reduced Minors for Linear Systems over   Commutative Rings
  In 1994, Sule presented the necessary and sufficient conditions of the feedback stabilizability of systems over unique factorization domains in terms of elementary factors and in terms of reduced minors. Recently, Mori and Abe have generalized his theory over commutative rings. They have introduced the notion of the generalized elementary factor, which is a~generalization of the elementary factor, and have given the necessary and sufficient condition of the feedback stabilizability. In this paper, we present two generalization of the reduced minors. Using each of them, we state the necessary and sufficient condition of the feedback stabilizability over commutative rings. Further we present the relationship between the generalizations and the generalized elementary factors. 
Kazuyoshi MORI