## Warfield Duality and Rank-one
Quasi-summands of Tensor
Products of Finite Rank Locally Free Modules over
Dedekind Domains

### (Journal of Algebra, 121(1989), pp. 129 - 138)

I love this little paper
(well, 10 printed pages).
As we all know, mathematics is a young wo/man's game,
but as far as I personally am concerned this paper,
written when I was almost fifty,
can hold its own with any of the ones that
established my reputation
when I was younger.
The main result is dramatically surprising,
so much so that I think I must have been crazy to have ever
dared to believe that such a thing might be true.
And the proof uses very simple principles.

What I especially like is that what the proof
uses is mostly a bunch of natural isomorphisms which are common currency
in ring theory,
but not much used by abelian group theorists.

Here's a brief quote from the referees report.
``This paper is a significant step
in the author's almost single-handed investigation
of tensor products of finite rank torsion-free modules
over Dedekind domains....
It was a distinct pleasure to read this elegant paper.
The author repeatedly demonstrates that,
with a careful choice of words,
complicated concepts can be expressed simply and understandably.
Unfortunately, his penchant for brevity does not extend to the
title, e.g. something like `Tensor products of locally free modules
over Dedekind domains' would be less informative
but also less overwhelming.''