def test_normal_closure():
# the normal closure of the trivial group is trivial
S = SymmetricGroup(3)
identity = Permutation([0, 1, 2])
closure = S.normal_closure(identity)
assert closure.is_trivial
# the normal closure of the entire group is the entire group
A = AlternatingGroup(4)
assert A.normal_closure(A).is_subgroup(A)
# brute-force verifications for subgroups
for i in (3, 4, 5):
S = SymmetricGroup(i)
A = AlternatingGroup(i)
D = DihedralGroup(i)
C = CyclicGroup(i)
for gp in (A, D, C):
assert _verify_normal_closure(S, gp)
# brute-force verifications for all elements of a group
S = SymmetricGroup(5)
elements = list(S.generate_dimino())
for element in elements:
assert _verify_normal_closure(S, element)
# small groups
small = []
for i in (1, 2, 3):
small.append(SymmetricGroup(i))
small.append(AlternatingGroup(i))
small.append(DihedralGroup(i))
small.append(CyclicGroup(i))
for gp in small:
for gp2 in small:
if gp2.is_subgroup(gp, 0) and gp2.degree == gp.degree:
assert _verify_normal_closure(gp, gp2)
def test_normal_closure():
# the normal closure of the trivial group is trivial
S = SymmetricGroup(3)
identity = Permutation([0, 1, 2])
closure = S.normal_closure(identity)
assert closure.is_trivial
# the normal closure of the entire group is the entire group
A = AlternatingGroup(4)
assert A.normal_closure(A).is_subgroup(A)
# brute-force verifications for subgroups
for i in (3, 4, 5):
S = SymmetricGroup(i)
A = AlternatingGroup(i)
D = DihedralGroup(i)
C = CyclicGroup(i)
for gp in (A, D, C):
assert _verify_normal_closure(S, gp)
# brute-force verifications for all elements of a group
S = SymmetricGroup(5)
elements = list(S.generate_dimino())
for element in elements:
assert _verify_normal_closure(S, element)
# small groups
small = []
for i in (1, 2, 3):
small.append(SymmetricGroup(i))
small.append(AlternatingGroup(i))
small.append(DihedralGroup(i))
small.append(CyclicGroup(i))
for gp in small:
for gp2 in small:
if gp2.is_subgroup(gp, 0) and gp2.degree == gp.degree:
assert _verify_normal_closure(gp, gp2)
def test_verify_normal_closure():
# verified by GAP
S = SymmetricGroup(3)
A = AlternatingGroup(3)
assert _verify_normal_closure(S, A, closure=A)
S = SymmetricGroup(5)
A = AlternatingGroup(5)
C = CyclicGroup(5)
assert _verify_normal_closure(S, A, closure=A)
assert _verify_normal_closure(S, C, closure=A)
