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Studies in Rings generalised Unique Factorisation Rings

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-64-<br />

Theoren12.46.<br />

Let R be a pri.me GUFR' and lv\ be a cyclic R-rnodule 0<br />

If N is a<br />

submodule of M such that<br />

(1) N is completely faithful and M/N unfaithful, or<br />

(2) N is unfaithful and M/N completely faithful Q<br />

Then N is a direct summand of Mo<br />

Proof:<br />

As <strong>in</strong> [ 24,<br />

lemma 2.3J.<br />

Theorem 2.47.<br />

Let R be a prime GUFR and A 98,C right R-moduleso<br />

Then t.h e exact sequence 0 ----t A ---+ B ~ C -----.,. 0<br />

splits provid9d anyone of the follow<strong>in</strong>g statements holds.<br />

(1) A is completely faithful and C is locally<br />

unfa.i t.h f u L,<br />

(2) A is unfaithful and C is completely faithful,<br />

(3) A is locally unfaithful and C is completely<br />

faithfulo<br />

Proof:<br />

As <strong>in</strong> [24, theorem 2 04J.<br />

Remark 2 04.8.<br />

For any macule M,<br />

it can be proved, us<strong>in</strong>g Zornvs

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