Opened 5 years ago

Last modified 5 years ago

#17620 new defect

broken is_isomorphic between matrix group and permutation group

Reported by: ncohen Owned by:
Priority: major Milestone: sage-6.5
Component: group theory Keywords:
Cc: vbraun Merged in:
Authors: Reviewers:
Report Upstream: N/A Work issues:
Branch: Commit:
Dependencies: Stopgaps:

Description (last modified by ncohen)

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

Change History (1)

comment:1 Changed 5 years ago by ncohen

  • Description modified (diff)
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