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i doesn't belong to QQbar ? Why ?

asked 2017-11-12 13:55:13 -0600

Emmanuel Charpentier gravatar image

updated 2017-11-13 03:30:54 -0600

tmonteil gravatar image

I do not understand this :

sage: sqrt(1) in QQbar
sage: sqrt(-2) in QQbar
sage: sqrt(-1) in QQbar

Can someone explain ?

Note that, however :

sage: [t[0] in QQbar for t in (x^2+1).roots(ring=QQbar)]
[True, True]
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answered 2017-11-12 18:12:08 -0600

tmonteil gravatar image

updated 2017-11-12 18:12:45 -0600

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.

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Asked: 2017-11-12 13:55:13 -0600

Seen: 52 times

Last updated: Nov 12 '17