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Dear Gap-Forum,

Richard Rossmanith wrote:

> 1. The HTML-GAP-Manual, Release 3.4 (10. Jul. 1994), states that

> > there is no generic way to test whether a [Ring] element is irreducible.

> Yes, there is:

>

> RingOps.IsIrreducible:=function(arg)

[...]

Yes, one could add this function. But in the general case then there would

be the problem to factor a ring element. In general this is even harder than

an irreducibility test (that gets called implicitely from 'Factors').

Therefore we did not add a function of this type. It would be possible,

however, to add, say, 'RationalsPolynomialsOps.IsIrreducible' or other

specific functions.

2. Usually, you use a list to define a polynomial. But maybe later on, you

want the list back, and you want that simply by using the command List(p).

You already mentioned problems with this function. The best way is to call

'ShiftedCoeffs(f.coefficients,f.valuation)' that will return the desired

coefficient list.

Best regards,

Alexander Hulpke

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