Why does not
GroupAlgebra(PermutationGroup([(1,2,3),(2,3,4)]),QQ).center_basis()
work when
codeGroupAlgebra(AlternatingGroup(4),QQ).center_basis()
does work?
The first command gives a long error message, terminating with the slightly bizzare
RuntimeError: There is a bug in the coercion code in Sage.
Both x (=()) and y (=()) are supposed to have identical parents but they don't.
In fact, x has parent 'Permutation Group with generators [(2,3,4), (1,2,3)]'
whereas y has parent 'Permutation Group with generators [(2,3,4), (1,2,3)]'
Original elements () (parent Permutation Group with generators [(2,3,4), (1,2,3)]) and () (parent Permutation Group with
generators [(2,3,4), (1,2,3)]) and maps
<class 'NoneType'> None
<class 'sage.structure.coerce_maps.DefaultConvertMap_unique'> (map internal to coercion system -- copy before use)
Coercion map:
From: Permutation Group with generators [(2,3,4), (1,2,3)]
To: Permutation Group with generators [(2,3,4), (1,2,3)]