fix latex method for laurent series element

[jhpalmieri]

In the Sage Notebook Bugreports, there is a report of an error with typesetting Laurent series elements:

sage: R.<a,b>=PolynomialRing(QQ)
sage: T.<x>=LaurentSeriesRing(R)
sage: latex(a*x+b*x)
'a + bx'

It ought to be (a+b)x, but the parentheses are missing. The attached patch should fix this.

Component: algebra

Author: John Palmieri

Reviewer: Minh Van Nguyen

Merged: Sage 4.1.1.rc1

Issue created by migration from https://trac.sagemath.org/ticket/6656

[sagetrac-mvngu]

Attachment: trac_6656-laurent.patch.gz

Attachment: trac_6656-reviewer.patch.gz

reviewer patch

[sagetrac-mvngu]

comment:1

Before the patch:

----------------------------------------------------------------------
| Sage Version 4.1, Release Date: 2009-07-09                         |
| Type notebook() for the GUI, and license() for information.        |
----------------------------------------------------------------------
sage: R.<a,b> = PolynomialRing(QQ)
sage: T.<x> = LaurentSeriesRing(R)
sage: y = a*x + b*x
sage: y._latex_()
'a + bx'
sage: latex(y)
a + bx

After the patch:

----------------------------------------------------------------------
| Sage Version 4.1.1.rc0, Release Date: 2009-07-29                   |
| Type notebook() for the GUI, and license() for information.        |
----------------------------------------------------------------------
**********************************************************************
*                                                                    *
* Warning: this is a prerelease version, and it may be unstable.     *
*                                                                    *
**********************************************************************
sage: R.<a,b> = PolynomialRing(QQ)
sage: T.<x> = LaurentSeriesRing(R)
sage: y = a*x + b*x
sage: y._latex_()
'\\left(a + b\\right)x'
sage: latex(y)
\left(a + b\right)x

Note that one can also obtain the LaTeX representation of an object through the latex() function. So I'm attaching a patch on top of John's that also calls that function. If John is OK with the patch trac_6656-reviewer.patch, then the ticket has positive review from me.

[jhpalmieri]

Reviewer: Minh Van Nguyen

[jhpalmieri]

comment:2

Sure, looks fine to me. Tests still pass with the reviewer patch.

[sagetrac-mvngu]

Merged: Sage 4.1.1.rc1

[sagetrac-mvngu]

comment:3

Merged both patches.