Beta Phase:
Square45 is currently in beta testing. Expect some features or content to be incomplete or missing.
45
English
Français
العربية
Deutsch
🏠
/
Mathematics
/
Group Theory
/
Normal Subgroup
Normal Subgroup
A subgroup that is invariant under conjugation by members of the group. Normal subgroups are crucial for constructing quotient groups.
📜
The statement of the theorem
A subgroup
N
N
N
of
G
G
G
is normal (denoted
N
⊴
G
N \trianglelefteq G
N
⊴
G
) if
g
n
g
−
1
∈
N
gng^{-1} \in N
g
n
g
−
1
∈
N
for all
n
∈
N
n \in N
n
∈
N
and
g
∈
G
g \in G
g
∈
G
.