Mike is correct about your first question: your confusion is between
coercion maps and conversion maps.
The function you're looking for is _mpoly_base_ring, which is written in
sage.rings.polynomial.multi_polynomial_ring_generic.pyx
David
On Wed, Feb 16, 2011 at 13:06, mmarco wrote:
> I already
On Wed, Feb 16, 2011 at 7:06 PM, mmarco wrote:
> I already new all that, but my question would be: "why
> S.has_coerce_map_from(R) returns False?"
Because S(r) is doing a "converion" rather than a "coercion".
Coercion is implicit and happens when doing arithmetic.
S.has_convert_map_from(R) should
I already new all that, but my question would be: "why
S.has_coerce_map_from(R) returns False?"
And the second question is "is there a command (or an easy way to
implement it) to recover QQ[x,y,z] from QQ[x][y][z] or any other
similar situation?"
I know how to deal with these cases by hand, but i
