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