I believe the matrix and permutation groups are quite old code, so UniqueRepresentation may not have been available at that time. The permutation group code does need updating; in particular, it is still an old-style parent:
sage: S.__class__.__mro__ (<class 'sage.groups.perm_gps.permgroup_named.SymmetricGroup_with_category' >, <class 'sage.groups.perm_gps.permgroup_named.SymmetricGroup'>, <class 'sage.groups.perm_gps.permgroup_named.PermutationGroup_symalt'>, <class 'sage.groups.perm_gps.permgroup_named.PermutationGroup_unique'>, <class 'sage.structure.unique_representation.CachedRepresentation'>, <class 'sage.groups.perm_gps.permgroup.PermutationGroup_generic'>, <type 'sage.groups.old.FiniteGroup'>, <type 'sage.groups.old.Group'>, <type 'sage.structure.parent_gens.ParentWithGens'>, <type 'sage.structure.parent_base.ParentWithBase'>, <type 'sage.structure.parent_old.Parent'>, <type 'sage.structure.parent.Parent'>, ... (Side note: We also should not be importing things like PermutationGroup_generic and PermutationGroupMorphism_id into the global namespace.) I don't see a reason off-hand why these should not be UniqueRepresentation subclasses. Best, Travis -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at https://groups.google.com/group/sage-devel. For more options, visit https://groups.google.com/d/optout.
