Opened 10 years ago
Closed 10 years ago
#12211 closed defect (fixed)
bug in equation checking for quasi projective/affine schemes
Reported by: | davideklund | Owned by: | AlexGhitza |
---|---|---|---|
Priority: | minor | Milestone: | sage-4.8 |
Component: | algebraic geometry | Keywords: | |
Cc: | Merged in: | sage-4.8.alpha6 | |
Authors: | David Eklund | Reviewers: | Volker Braun |
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description (last modified by )
The method _check_satisfies_equations
of the class AlgebraicScheme_quasi
checks whether a point p lies on the complement of a scheme Y in a scheme X.
If one of the equations defining Y vanishes, then p is judged not a point on X-Y, but it could be that some other equation defining Y does not vanish.
Example:
sage: P.<x, y, z, w> = ProjectiveSpace(3, QQ) sage: S = P.subscheme([x]) sage: T = P.subscheme([y, z]) sage: U = T.complement(S) sage: U._check_satisfies_equations([0,0,1,1]) ... TypeError: Coordinates [0, 0, 1, 1] do not define a point on Quasi-projective subscheme X - Y of Projective Space of dimension 3 over Rational Field, where X is defined by: x and Y is defined by: y, z
Attachments (2)
Change History (7)
Changed 10 years ago by
comment:1 Changed 10 years ago by
comment:2 Changed 10 years ago by
- Reviewers set to Volker Braun
Can you add your example to the doctest?
comment:3 Changed 10 years ago by
- Description modified (diff)
- Status changed from new to needs_review
comment:5 Changed 10 years ago by
- Merged in set to sage-4.8.alpha6
- Resolution set to fixed
- Status changed from positive_review to closed
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Fixes the bug.