Use variable names instead of symbolic variables

[jdemeyer]

Where possible, use QQ["x"] instead of QQ[x] to construct polynomial rings. After #10483, the latter will be deprecated.

CC: @simon-king-jena @rwst

Component: basic arithmetic

Author: Simon King, Ralf Stephan, Jeroen Demeyer

Branch/Commit: ee4548f

Reviewer: Jeroen Demeyer, Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/23337

[jdemeyer]

Branch: u/jdemeyer/ticket/23337

[sagetrac-git]

Commit: d1f6fff

[sagetrac-git]

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

d1f6fff

Use variable names instead of symbolic variables

[jdemeyer]

Reviewer: Jeroen Demeyer

[sagetrac-git]

Changed commit from d1f6fff to 52de325

[sagetrac-git]

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

52de325

Use variable names instead of symbolic variables

[tscrim]

comment:5

There are some doctest failures (see patchbot). There are some actual changes in output type, but I am not sure if they are (more) correct or not. I would think some of them are actual regressions since they do not contain as much information (i.e., ZZ[x][y] has slightly different structure for things like factoring compared to ZZ[x,y]).

[sagetrac-git]

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

ee4548f

Use variable names instead of symbolic variables