设尺是整环,S=R-0.设肘是无挠R-模,N是肘的子模,且rank(M)=n,rank(N)=i〈n,则对任意j(i≤j〈n),存在M的素子模A,使得,v A,且rank(A)=j..同时,讨论了模上的主理想定理,证明了若R是SM整环,则以下各条等价:(1)任意投射R-模有PIT,(2)R有PIT,(3)对R中任意高度为1的素理想p,R,是赋值环,(4)对月中任意高度为1的素理想p,Rp,是离散赋值环.
Let R be an integral domain, S =R -0, and let N be a submodule of a torsion-free R-module M such that rank(M) = n and rank (N) = i 〈 n. Then for all j with i ≤ j 〈 n there exists a prime submodule A of M such that N A and rank ( A ) =j. Moreover, we discuss the principal ideal theorem for modules and prove that if R is an SM domain, then the following conditions are equivalent : ( 1 ) the PIT holds for every projective R-module, (2) the PIT holds for R(2) , ( 3 ) the local ring Rp is a valuation ring for every height 1 prime ideal p of R, and (4) the local ring Rp is a discrete valuation ring for every height 1 prime ideal p of R.