#10161: AlgebraicNumber comparisons wrong/fail
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Reporter: vbraun | Owner: was
Type: defect | Status: new
Priority: major | Milestone:
Component: number theory | Resolution:
Keywords: | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Dependencies:
Stopgaps: |
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Comment (by mhansen):
The issue is actually:
{{{
sage: map(hash, (x,y,z))
[1, 1, -3730706066237751940]
}}}
If two things have the same hash and compare equal, then they are the same
as far as dictionaries are concerned:
{{{
sage: d = {}
sage: d[x] = x
sage: d[y] = y
sage: len(d)
1
sage: id(y)
110133424
sage: id(d[x])
110133424
}}}
One fix would be to change the hash of rational numbers. Although, I
think their hash function was designed to be consistent with the integers.
--
Ticket URL: <http://trac.sagemath.org/ticket/10161#comment:2>
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