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Studies in Rings generalised Unique Factorisation Rings

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-52-<br />

Proof:<br />

As <strong>in</strong> [22, Proposition 2.10J.<br />

Theorem 2.26.<br />

prime GUFR s ,<br />

Every semiprime GUFR is a sub direct product of<br />

Proof:<br />

Then<br />

n<br />

i=l P. 1<br />

P be the m<strong>in</strong>imal prime ideals of R.<br />

n<br />

= 0, s<strong>in</strong>ce R<br />

is semi prime. Thus, if we<br />

show that RIp., for 1 ~ i ~ n, is a prime GUFR, then<br />

1<br />

the theorem follows from proposition 2.25.<br />

It is clear<br />

that Rip· is a prime Noetherian r<strong>in</strong>g, for 1 $ i ~ n.<br />

1<br />

Let pip· be a non zero prime ideal of Rip.. Then P is a<br />

1 1<br />

non-m<strong>in</strong>imal prime ideal of R with P. < Po So ther~<br />

1 -<br />

exists an element a e P such that aR=Ra is <strong>in</strong>vertible.<br />

By lemma 2.19, a ~ P. and thus a is a non zero element<br />

1<br />

o f RIP. with a(R/ P .) = (Rip· )a, ~Jhere a = a+P.. A1 so<br />

1 l l 1<br />

is the simple Art<strong>in</strong>ian quotient r<strong>in</strong>g of Rip·.<br />

Now Rip.<br />

1 1<br />

is a prime GUFR follows from the fact that ~ £ pip ..<br />

l<br />

PRINCIPAL IDEAL RINGS<br />

It is well known<br />

that every commutative pr<strong>in</strong>cipal<br />

ideal doma<strong>in</strong> is a UFO. We prove an analogous result for<br />

GUFRs.

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