Bill Allombert on Sat, 16 Nov 2019 19:04:39 +0100

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Re: List of polynomial coefficients in GP

On Fri, Nov 15, 2019 at 05:55:15PM +0000, Jacques Gélinas wrote:
> >(Bill Allombert)  Fundamentally this is a bug in subst:
> Looks like a feature of Vec, which simplifies its input, and I would not want to change that.
>              Vec(Pol(subst(1*u+2*P-6,u,x+3))) == [1, 2*P - 3]
>              Vec(Pol(subst(0*u+2*P-6,u,x+3))) == [2, -6]

Vec does not simplify its input, you are misunderstanding what Pol is
doing there (i.e nothing), but you are on the right track!

Vec(u^0*subst(0*u+2*P-6,u,x+3)) == [2*P-6]