Opened 3 years ago

#22414 new defect

check for subs of AsymptoticExpansion

Reported by: dkrenn Owned by:
Priority: major Milestone: sage-7.6
Component: asymptotic expansions Keywords:
Cc: cheuberg, behackl Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description

sage: A.<n> = AsymptoticRing('n^ZZ', QQ, default_prec=3)
sage: n
n
sage: _.subs(n=1/(2-1/n))
1/2 + 1/4*n^(-1) + 1/8*n^(-2) + O(n^(-3))
sage: _.subs(n=1/(2-1/n))
O(1)

is wrong (the two substitutions are equal to the identity).

Similarly,

sage: n.subs(n=1/(2-1/n))
1/2 + 1/4*n^(-1) + 1/8*n^(-2) + O(n^(-3))
sage: _.subs(n=A(1/2))
O(1)

Aim: add a check 1/f is o(1) to .subs(n=f).

Change History (0)

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