Endomorphisms of the Semigroup of Nonnegative Invertible Matrices of Order Two Over Commutative Ordered Rings

摘要

Abstract Let R be a linearly ordered commutative ring with 1/2 generated by its invertible elements, G2(R) be the subsemigroup in GL2(R) consisting of all matrices with nonnegative elements. In this paper, we describe endomorphisms of the given semigroup.