Handle zero coefficients when converting asymptotic rings

[cheuberg]

sage: CR.<Z> = QQ['Z']
sage: CR_mod = CR.quotient((Z^2 - 1)*CR)
sage: R.<x> = AsymptoticRing(growth_group='x^NN', coefficient_ring=CR)
sage: R_mod = R.change_parameter(coefficient_ring=CR_mod)
sage: e = 1 + x*(Z^2-1)
sage: R_mod(e)
Traceback (most recent call last):
...
ValueError: Cannot include Z^2 - 1*x with parent Exact Term Monoid
x^((Non negative integer semiring)) with coefficients in Univariate
Polynomial Ring in Z over Rational Field in Asymptotic Ring
<x^((Non negative integer semiring))> over Univariate Quotient Polynomial
Ring in Zbar over Rational Field with modulus Z^2 - 1
> *previous* ValueError: Zero coefficient 0 is not allowed in Exact
Term Monoid x^((Non negative integer semiring)) with coefficients
in Univariate Quotient Polynomial Ring in Zbar over Rational Field
with modulus Z^2 - 1.

Depends on #19528

CC: @dkrenn @behackl

Component: asymptotic expansions

Author: Clemens Heuberger, Daniel Krenn

Branch/Commit: 3c109a2

Reviewer: Daniel Krenn, Clemens Heuberger

Issue created by migration from https://trac.sagemath.org/ticket/19921

[cheuberg]

Branch: u/cheuberg/asy/conversion-zero-coefficient

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. This was a forced push. New commits:

0159226

Trac #19921: Handle zero coefficients when converting asymptotic rings

[sagetrac-git]

Commit: 0159226

[cheuberg]

Author: Clemens Heuberger

[dkrenn]

Changed branch from u/cheuberg/asy/conversion-zero-coefficient to u/dkrenn/asy/conversion-zero-coefficient

[dkrenn]

comment:6

LGTM. I've added one commit; please cross-review and if ok, then set this ticket to positive_review.

---

New commits:

25e2348

use ZeroCoefficientError in create_summand as well

[dkrenn]

Changed commit from 0159226 to 25e2348

[cheuberg]

comment:7

This should depend on the new code of mutable_poset.map which allows None and is not merged yet.

[cheuberg]

Changed branch from u/dkrenn/asy/conversion-zero-coefficient to u/cheuberg/asy/conversion-zero-coefficient

[cheuberg]

New commits:

421e377	mutable poset map: remove elements ``None``
1d28240	term monoid: write change_parameter
2c37889	correct a bug in change_parameter
bdcb72b	write map_coefficients
8a71ba3	Trac #19528: simplification of documentation
3c109a2	Trac #19921: Merge #19528

[cheuberg]

Dependencies: #19528

[cheuberg]

Changed commit from 25e2348 to 3c109a2

[cheuberg]

Changed author from Clemens Heuberger to Clemens Heuberger, Daniel Krenn

[cheuberg]

comment:10

Replying to @dkrenn:

LGTM. I've added one commit; please cross-review and if ok, then set this ticket to positive_review.

Thank you, cross-reviewed. This is a conditional positive modulo #19528.

[cheuberg]

Reviewer: Daniel Krenn, Clemens Heuberger

[vbraun]

Changed branch from u/cheuberg/asy/conversion-zero-coefficient to 3c109a2