#18595: Big Oh terms and equality
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Reporter: behackl | Owner:
Type: defect | Status: new
Priority: major | Milestone: sage-6.8
Component: commutative algebra | Resolution:
Keywords: powerseries, asymptotics | Merged in:
Authors: | Reviewers:
Report Upstream: N/A | Work issues:
Branch: | Commit:
Dependencies: | Stopgaps:
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Comment (by nbruin):
It is not clear to me why the behaviour illustrated in the ticket is not
desirable. It is certainly consistent with p-adics and with arithmetic:
{{{
sage: PSR.<x> = PowerSeriesRing(ZZ)
sage: a=x
sage: b=a+O(x^2)
sage: (a-b).is_zero()
True
sage: a==b
True
}}}
so changing the current behaviour would also require that `O(x^2) != 0`.
Also, checking whether an O-term is present is quite straightforward:
{{{
sage: (x+O(x^2)).precision_absolute()
2
sage: (x).precision_absolute()
+Infinity
}}}
I'd think close as Invalid. Please comment if you think otherwise.
--
Ticket URL: <http://trac.sagemath.org/ticket/18595#comment:2>
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