Theorem 15.2.
Assuming that:
A
is a
G
-module
H
⊴
G
a normal subgroup
Then
there is an inflation restriction exact sequence
0
→
H
1
(
G
∕
H
,
A
H
)
→
inf
H
1
(
G
,
A
)
→
res
H
1
(
H
,
A
)