Ilya Zakharevich on Thu, 4 Jul 2002 08:41:13 -0400

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Re: polcoeff() mystery

On Thu, Jul 04, 2002 at 02:23:08PM +0200, Bill Allombert wrote:
> There are three things to keep in mind:
> 1) GP know only about univariate polynomials over a field.

"Currently".  Given Groebner bases, this should be easy to fix.

> 2) 'foo^0 is printed as 1 for every foo., but is internally still 'foo^0
> 3) The same happen for zero complex, quadratic and algebraic numbers.
> There is no such thing as x^2+y*x+z.

Why?  *This* is what was confusing me so much when "inefficient"
internal representation was mentioned.  I was doing \x, and saw
something very efficient.

Which algorithsms assume that a poly is "filled"?  Maybe t_POL should
be updated by an extra field `a "compressed" version of the poly'; if
only one of the fields is present, but another is needed, it may be
filled on a "as needed" basis...

> Maybe a print function that output 'foo^0 as 'foo^0 not 1 could be useful.

\x *must*.