Revision history [back]
 | 1 | initial version |
Ues GF(4) (finite field) rather Zmod(4) (fonite ring not known to be a field) :
sage: reset()
sage: R.<x>=Zmod(4)[]
sage: Q.<a>=R.quotient((x^2,2*x))
sage: len(list(Q))
---------------------------------------------------------------------------
NotImplementedError Traceback (most recent call last)
Input In [242], in <cell line: 1>()
----> 1 len(list(Q))
File /usr/local/sage-9/src/sage/rings/ring.pyx:220, in sage.rings.ring.Ring.__iter__()
218 NotImplementedError: object does not support iteration
219 """
--> 220 raise NotImplementedError("object does not support iteration")
221
222 def __len__(self):
NotImplementedError: object does not support iteration
But :
sage: R.<x>=GF(4)[]
sage: Q.<a>=R.quotient((x^2,2*x))
sage: len(list(Q))
16
sage: list(Q)
[0,
z2,
z2 + 1,
1,
z2*a,
z2*a + z2,
z2*a + z2 + 1,
z2*a + 1,
(z2 + 1)*a,
(z2 + 1)*a + z2,
(z2 + 1)*a + z2 + 1,
(z2 + 1)*a + 1,
a,
a + z2,
a + z2 + 1,
a + 1]
HTH,
| | 2 | No.2 Revision |
Ues Use GF(4) (finite field) rather Zmod(4) (fonite (finite ring not explicitely known to be a field) :
sage: reset()
sage: Zmod(4).is_field()
False
sage: GF(4).is_field()
True
sage: R.<x>=Zmod(4)[]
sage: Q.<a>=R.quotient((x^2,2*x))
sage: len(list(Q))
---------------------------------------------------------------------------
NotImplementedError Traceback (most recent call last)
Input In [242], in <cell line: 1>()
----> 1 len(list(Q))
File /usr/local/sage-9/src/sage/rings/ring.pyx:220, in sage.rings.ring.Ring.__iter__()
218 NotImplementedError: object does not support iteration
219 """
--> 220 raise NotImplementedError("object does not support iteration")
221
222 def __len__(self):
NotImplementedError: object does not support iteration
But :
sage: R.<x>=GF(4)[]
sage: Q.<a>=R.quotient((x^2,2*x))
sage: len(list(Q))
16
sage: list(Q)
[0,
z2,
z2 + 1,
1,
z2*a,
z2*a + z2,
z2*a + z2 + 1,
z2*a + 1,
(z2 + 1)*a,
(z2 + 1)*a + z2,
(z2 + 1)*a + z2 + 1,
(z2 + 1)*a + 1,
a,
a + z2,
a + z2 + 1,
a + 1]
HTH,
