We consider a class of domains R containing a maximal ideal N such that R i
s not complete with respect to the n-adic topology, but T = R-N is a comple
te DVR. Such domains are called T-large because of the way to construct the
m. We characterize a T-large domain R to be of the form R = T boolean AND V
, where V is a mildly restricted valuation domain of Q, the field of fracti
ons of T, We show that the completion ir of V has infinite rank as a V-modu
le. We investigate finite rank torsion-free modules M over a T-large domain
R which are Hausdorff in the N-adic topology. Making use of known results
on V-modules, we obtain the following results: there exist indecomposable t
orsion-free Hausdorff R-modules of any fixed rank n; every cotorsion-free H
ausdorff R-algebra of rank n is the endomorphism algebra of a torsion-free
module of rank 3n; the Krull-Schmidt theorem fails, that is, there exist fi
nite rank torsion-free Hausdorff R-modules which admit nonisomorphic decomp
ositions into indecomposable summands.