Opened 17 months ago
Last modified 5 weeks ago
#28150 new defect
Bugs in subgroups of a subgroup of an abelian group
Reported by: | mathzeta2 | Owned by: | |
---|---|---|---|
Priority: | major | Milestone: | sage-9.3 |
Component: | group theory | Keywords: | abelian group fpsac2019 |
Cc: | Merged in: | ||
Authors: | Reviewers: | ||
Report Upstream: | N/A | Work issues: | |
Branch: | Commit: | ||
Dependencies: | Stopgaps: |
Description
The following raises an exception at least on versions 8.7 and 8.9.beta1:
G = AbelianGroup([3, 3]) H = G.subgroup([G.gen()]) H.subgroups() [snip] RuntimeError: Gap produced error output Error, families of <gens> and <M> are different executing H:=Subgroup(G,gensH);
From a brief overview of src/sage/groups/abelian_gps/abelian_group.py the docs for AbelianGroup_class.subgroup()
mentions "The 'big' group must be defined using 'named' generators". But trying
G.<a, b> = AbelianGroup([3, 3]) H = G.subgroup([a]) H.subgroups()
gives the same error. Also AbelianGroup_subgroup.gen()
does not have a default argument for the first generator, like AbelianGroup_class.gen()
and many of the gen()
methods in Sage.
Change History (4)
comment:1 Changed 17 months ago by
- Keywords fpsac2019 added; fpsac removed
comment:2 Changed 11 months ago by
- Milestone changed from sage-8.9 to sage-9.1
comment:3 Changed 7 months ago by
- Milestone changed from sage-9.1 to sage-9.2
Moving tickets to milestone sage-9.2 based on a review of last modification date, branch status, and severity.
comment:4 Changed 5 weeks ago by
- Milestone changed from sage-9.2 to sage-9.3
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