On Oct 12, 2007, at 11:15 AM, Joel B. Mohler wrote:
sage: is_FractionField(QQ)
False
Any field is a fraction field (of itself), and any non-field is *not*
a fraction field, so mathematically is_FractionField is kind of
stupid. I suppose it really means is_implemented_as_a_fraction_field.
On 10/12/07, Joel B. Mohler [EMAIL PROTECTED] wrote:
I find the two following results contradictory:
sage: FractionField(ZZ) is QQ
True
sage: is_FractionField(QQ)
False
Is that a bug?
No. all of the many dozens of is_* methods do *type* checking.
They are not checking some abstract
On 10/12/07, Joel B. Mohler [EMAIL PROTECTED] wrote:
Yes, I realize that. It just seemed to me that if I wanted to utilize simple
type-checking, I would use isinstance (since I'm a python programmer). In
fact, the is_* functions are confusing to me for this very reason -- i.e.
they must do
On Friday 12 October 2007 11:25, William Stein wrote:
sage: FractionField(ZZ) is QQ
True
sage: is_FractionField(QQ)
False
No. all of the many dozens of is_* methods do *type* checking.
They are not checking some abstract mathematical properties.
There is a specific data type in Sage
