Nonzero nonunit non-product-of-irreducibles is reducible?

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SUMMARY

The claim that a nonzero nonunit element in an integral domain R, which is not a product of irreducible elements, is reducible is false. The discussion establishes that if a nonzero nonunit element x is irreducible, it cannot simultaneously be a product of irreducibles. The counterexample provided is the integers, demonstrating that not all nonzero nonunit elements are reducible. Therefore, the assertion is disproven through logical contradiction.

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Homework Statement


Claim
Let R be an integral domain. Then a nonzero nonunit element in R that is not a product of irreducible elements is reducible.

Is this claim true?


Homework Equations





The Attempt at a Solution


By definition, a product of irreducibles is reducible because irreducibles are not units. This implies if nonzero nonunit x is irreducible then it is not a product of irreducible elements.

I've tried to prove the above claim by contradiction supposing nonzero nonunit x is both not a product of irreducibles and x is irreducible. But by the above observation, I couldn't; the fact that x is irreducible and the fact that x is nonzero nonunit and not a product of irreducibles are consistnet.

Logically, the claim asserts that if x is nonzero nonunit and not a product of irreducibles then x is reducible. Let's call this statement P -> Q. And the above observation yields, kinda, that ~P -> Q. But this this yields every nonzero nonunit element in R is reducible, which is absurd.

So the claim should be false?
 
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The claim is false. The integers provide a good counter-example.
 
Thanks a lot!
 

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