Ilya Zakharevich on Tue, 2 Jul 2002 09:16:06 -0400

 Re: polcoeff() mystery

```On Tue, Jul 02, 2002 at 01:30:38PM +0200, Karim BELABAS wrote:
> ? install(voir,"vGD-1,L,")
> ? T = x^2+y*x+z;
> ? voir(T) \\ _not_ the same as voir(%), i.e \x
>
> [&=00a5d26c] POL(lg=5,CLONE):15000005  (+,varn=0,lgef=5):40000005  00a5d2d4
> 00a5d2a0  00a5d280
>   coef of degree 0 = [&=00a5d2d4] POL(lg=3):14000003 (+,varn=7,lgef=3):40070003  00a5d2c4
>     coef of degree 0 = [&=00a5d2c4] POL(lg=4):14000004 (+,varn=8,lgef=4):40080004  00a5d2bc  00a5d2b0
>       coef of degree 0 = [&=00a5d2bc]
>       coef of degree 1 = [&=00a5d2b0]
>   coef of degree 1 = [&=00a5d2a0] POL(lg=4):14000004 (+,varn=7,lgef=4):40070004  00a5d298  00a5d28c
>     coef of degree 0 = [&=00a5d298]
>     coef of degree 1 = [&=00a5d28c] [...]
>
> See the extra layer ?

Is it *always* present?  Should not '=' in 'T=...' call simplify()?

Do you mean that to have efficient polynomial arithmetic, it is enough
to insert enough calls to simplify(), as in

T = simplify(x^2+y*x+z)

?

> Hope this is clearer,

Much clearer in some respects, much more obscure in others...

Ilya
```