Studies in Rings generalised Unique Factorisation Rings
Studies in Rings generalised Unique Factorisation Rings
Studies in Rings generalised Unique Factorisation Rings
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-89-<br />
Def<strong>in</strong>ition 303.4<br />
Let R be a 5ubr<strong>in</strong>g of Q. We say that R is classicaly<br />
right (left) <strong>in</strong>tegrally closed <strong>in</strong> Q,<br />
if R conta<strong>in</strong>s a nv<br />
element y of Q for which there exiGt elements a<br />
o<br />
,a1,···,a<br />
n-<br />
1<br />
n-l<br />
of R such that yn = a + ya o l<br />
+ + Y an-1<br />
n-l)<br />
a IY • n-<br />
R is classically <strong>in</strong>tegrally<br />
closed <strong>in</strong> Q if it is classically right and left <strong>in</strong>tegrally<br />
closed <strong>in</strong> Q [14J.<br />
Lemma 3 03.5.<br />
Suppose the r<strong>in</strong>g R is <strong>in</strong>tegrally closed and is an order<br />
<strong>in</strong> a r<strong>in</strong>g Q. Then the follow<strong>in</strong>g assertions are true.<br />
(1) bmb-1 € Rand b-1mb E R for all b e eR (0) and m E: R.<br />
(2) If A is a f<strong>in</strong>itely generated submodule of OR and<br />
f e End A, then there exists d (; R such tria t f(a)=da<br />
for all a € A.<br />
Proof<br />
As <strong>in</strong> [14, lemma 2 012J.<br />
Theorem 3036.<br />
Let R be a s ernipr i.me r i.qh t I\loetherian r<strong>in</strong>g \vith the<br />
~ ern i r; i mp 1 (; Arti n i a n Cl \J 0 t i (ln t .r i fl (1 lJ. ~-; u IJ}) 0 ~) e .il [;() t h