A Class Of Abelian Groups

Abstract

1. Introduction. If M is any finite set we define a chain on M as a mapping f of M into the set of ordinary integers. If a ∈ M then f(a) is the coefficient of a in the chain f. The set of all a ∈ M such that f(a) ≠ 0 is the domain |f| of f. If |f| is null, that is if f(a) = 0 for all a, then f is the zero chain on M. If M is null it is convenient to say that there is just one chain, a zero chain, on M.