摘要
Let R be an associative(not necessary commutative)ring.In this paper,we give some properties of Hom-faithful and Hom-cofaithful R-modules.We investigate P-self-orthogonal R-modules and PC-projective dimensions,and give a characterization when the inequality{Рc-pdU,Pc-pdW}is strict for an exact sequence0→U→V→W→0.Dually,we study Π-self-orthogonal modules and IC-injective di-mensions,and give a similar characterization when the inequalityIc-idV≤max{IcidU,Ic-IDW}is strict.
作者
何东林
李煜彦
HE Dong-lin;LI Yu-yan(Department of Mathematics,Longnan Teachers College,Longnan,742500,China)
基金
the 2019 Scienti c Research Projects in Universities of Gansu Province(2019B-224)
the 2020 Gansu University Innovation Fund Projective(2020A-277)。
