Semirings abound in the mathematical world around us. The first mathematical structure we encounter-the set of natural numbers is a semiring. Other semirings arise naturally in such diverse areas of mathematics as combinatorics, functional analysis, topology, graph theory, Euclidean geometry, probability theory, commutative and non-commutative ring theory, optimization theory, discrete event dynamical systems, automata theory, formal language theory and the mathematical modeling of quantum physics and parallel computation systems. Это и многое другое вы найдете в книге Some Studies on Semirings and Ordered Semrings (Manjula Karre and T. Vasanthi)