isWellDefined for RingMap fails sometimes
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Description
isWellDefined is not correct in the following case. If QQ is replaced with a finite field, e.g. ZZ/32003, or GF(27), then it works.
kk = QQ
R = kk[x,y]/(x^4-3, y^3-2);
phi = map(R, kk, {})
isWellDefined phi -- gives "error: no ambient ring present"
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Research direction
Start by reproducing the isWellDefined phi example with kk = QQ, R = kk[x,y]/(x^4-3, y^3-2), and phi = map(R, kk, {}). Compare this with the finite-field cases that work; the issue is done when the rational case no longer reports "no ambient ring present" while the working cases remain correct.
Written by the indexing model from the issue text.
Assessment
- Domain
- backend
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 25/100