I do not understand this :
sage: sqrt(1) in QQbar
True
sage: sqrt(-2) in QQbar
True
sage: sqrt(-1) in QQbar
False
Can someone explain ?
Note that, however :
sage: [t[0] in QQbar for t in (x^2+1).roots(ring=QQbar)]
[True, True]
This is definitely a bug, thanks for reporting! As you can see in the source code:
sage: QQbar.__contains__??
the test:
elif EQ:
which corresponds to:
sage: bool(I == QQbar(I))
leads to:
TypeError: unsupported operand parent(s) for +: 'Number Field in I with defining polynomial x^2 + 1' and 'Algebraic Field'
which is catched to return False.
I have opened trac ticket 24209 for this.
EDIT This issue is fixed now (Sage 9.4-beta3):
sage: sqrt(-1) in QQbar
True
sage: I in QQbar
True
Until Sage 9.3.rc4 I in QQbar returns False. Starting with Sage 9.3.rc5 it returns True.
It must have been solved by Sage Trac ticket 31628: fix/improve conversions to QQbar and AA.
Asked: 2017-11-12 20:55:13 +0200
Seen: 594 times
Last updated: Jun 27
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Still the same bug on SageMath version 8.2, Release Date: 2018-05-05 . Nobody fix this? 0.0
1) This is not an answer...
2) see the mentioned ticket (as well as thetickets it refers to) to understand why there is not quick-and-easy fix for this one...
@Emmanuel Charpentier thanks for 1), my mistake. I decided to move back to linux, so my comment doesnt have sense anymore. Thanks for the feedback!