Division by monomials in LaurentPolynomialRings should not be in the fraction field

[miguelmarco]

Right now, if we divide a Laurent Polynomial by a monomial, the result will live in the fraction field of the corresponding polynomial ring:

sage: R.<s,q,t>=LaurentPolynomialRing(QQ)
sage: f=s^2*q+q^(-1)*t
sage: f
s^2*q + q^-1*t
sage: f.parent()
Multivariate Laurent Polynomial Ring in s, q, t over Rational Field
sage: f/s
(s^2*q^2 + t)/(s*q)
sage: (f/s).parent()
Fraction Field of Multivariate Polynomial Ring in s, q, t over Rational Field

But monomials here are units, so dividing by them should result in an element of the same ring.

This patch solves this:

sage: R.<s,q,t>=LaurentPolynomialRing(QQ)
sage: f=s^2*q+q^(-1)*t
sage: f.parent()
Multivariate Laurent Polynomial Ring in s, q, t over Rational Field
sage: f/s
s*q + s^-1*q^-1*t
sage: (f/s).parent()
Multivariate Laurent Polynomial Ring in s, q, t over Rational Field

CC: @roed314 @loefflerd

Component: commutative algebra

Keywords: Laurent polynomials

Author: Miguel Marco

Branch/Commit: 91f7773

Reviewer: Frédéric Chapoton

Issue created by migration from https://trac.sagemath.org/ticket/17520

[miguelmarco]

Branch: u/mmarco/ticket/17520

[fchapoton]

comment:2

is this needs_review ?

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New commits:

e278645

Division by monomials in LaurentPolynomialRing stays in the ring.

[fchapoton]

Commit: e278645

[miguelmarco]

comment:3

Yes, sorry to forget.

[fchapoton]

comment:4

ok, looks good to me.
I just made a few cosmetic changes in the doc, so I allow myself to put the ticket to positive
review.

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New commits:

487ff8e	Merge branch 'u/mmarco/ticket/17520' into 6.7
91f7773	trac #17520 review commit (minor details)

[fchapoton]

Changed commit from e278645 to 91f7773

[fchapoton]

Changed branch from u/mmarco/ticket/17520 to public/ticket/17520

[fchapoton]

Reviewer: Frédéric Chapoton

[vbraun]

Changed branch from public/ticket/17520 to 91f7773