Show that the set of the R-homomorphism $A\rightarrow B$ with factorization through an injective module is an subgroup of $Hom_{R}(A,B)$.
It's a question from my last test in abstract algebra, that I can't solve.
Show that the set of the R-homomorphism $A\rightarrow B$ with factorization through an injective module is an subgroup of $Hom_{R}(A,B)$.
It's a question from my last test in abstract algebra, that I can't solve.
Hint: This just follows from the fact that a direct sum of two injective modules is injective.