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Brazil Undergrad MO
2018 Brazil Undergrad MO
25
25
Part of
2018 Brazil Undergrad MO
Problems
(1)
Additive group
Source: Brazil Undergrad MO - Galois-Noether 2018 #25
11/26/2019
Consider the
Z
/
(
10
)
\mathbb {Z} / (10)
Z
/
(
10
)
additive group automorphism group of integers module
10
10
10
, that is,
A
=
{
ϕ
:
Z
/
(
10
)
→
Z
/
(
10
)
∣
ϕ
−
a
u
t
o
m
o
r
p
h
i
s
m
}
A = \left \{\phi: \mathbb {Z} / (10) \to \mathbb {Z} / (10) | \phi-automorphism \right \}
A
=
{
ϕ
:
Z
/
(
10
)
→
Z
/
(
10
)
∣
ϕ
−
a
u
t
o
m
or
p
hi
s
m
}
topology
Brazilian Undergrad MO
group theory