Opened 8 years ago

Last modified 4 weeks ago

#17620 new defect

Fix `is_isomorphic` for matrix group and permutation group

Reported by: Nathann Cohen Owned by:
Priority: major Milestone:
Component: group theory Keywords:
Cc: Samuel Lelièvre, Volker Braun Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

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Description (last modified by Samuel Lelièvre)

This does not work:

sage: g1 = groups.permutation.PGL(2,2)
sage: g2 = groups.matrix.GO(3,2)
sage: g2.is_isomorphic(g1)
...
AttributeError: 'PGL_with_category' object has no attribute 'gap'

A simple hack seems to work

sage: g1.gap = g1._gap_
sage: g2.is_isomorphic(g1)
True

Though I was not able to find where _gap_ was defined on permutation groups.

Note that g1.is_isomorphic(g2) fails for another reason

sage: g1.is_isomorphic(g2)
...
TypeError: right must be a permutation group

Related:

Change History (3)

comment:1 Changed 8 years ago by Nathann Cohen

Description: modified (diff)

comment:2 Changed 8 months ago by Samuel Lelièvre

Cc: Samuel Lelièvre added
Description: modified (diff)
Summary: broken is_isomorphic between matrix group and permutation groupFix `is_isomorphic` for matrix group and permutation group

comment:3 Changed 4 weeks ago by Matthias Köppe

Milestone: sage-6.5
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