Abstract:
We obtain a description of quasi-endomorphism rings of torsion-free
Abelian groups $G$ of rank $4$, quasi-decomposable into a direct sum of
groups $A_1$ and $A_2$ of rank $1$ and a strongly indecomposable group $B$ of rank $2$
in the case where the quasi-homomorphism group
$\mathbb {Q} \otimes \operatorname{Hom}(A_2,B)$ has rank $2$.