Database
BASIC ALGEBRAIC STRUCTURES
Groups
Abelian groups
Internal direct products
dprdf
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dprdf2
Metamath Proof Explorer
Ascii
Unicode
Theorem
dprdf
Description:
The function
S
is a family of subgroups.
(Contributed by
Mario Carneiro
, 25-Apr-2016)
Ref
Expression
Assertion
dprdf
⊢
G
dom
⁡
DProd
S
→
S
:
dom
⁡
S
⟶
SubGrp
⁡
G
Proof
Step
Hyp
Ref
Expression
1
reldmdprd
⊢
Rel
⁡
dom
⁡
DProd
2
1
brrelex2i
⊢
G
dom
⁡
DProd
S
→
S
∈
V
3
2
dmexd
⊢
G
dom
⁡
DProd
S
→
dom
⁡
S
∈
V
4
eqid
⊢
dom
⁡
S
=
dom
⁡
S
5
eqid
⊢
Cntz
⁡
G
=
Cntz
⁡
G
6
eqid
⊢
0
G
=
0
G
7
eqid
⊢
mrCls
⁡
SubGrp
⁡
G
=
mrCls
⁡
SubGrp
⁡
G
8
5
6
7
dmdprd
⊢
dom
⁡
S
∈
V
∧
dom
⁡
S
=
dom
⁡
S
→
G
dom
⁡
DProd
S
↔
G
∈
Grp
∧
S
:
dom
⁡
S
⟶
SubGrp
⁡
G
∧
∀
x
∈
dom
⁡
S
∀
y
∈
dom
⁡
S
∖
x
S
⁡
x
⊆
Cntz
⁡
G
⁡
S
⁡
y
∧
S
⁡
x
∩
mrCls
⁡
SubGrp
⁡
G
⁡
⋃
S
dom
⁡
S
∖
x
=
0
G
9
3
4
8
sylancl
⊢
G
dom
⁡
DProd
S
→
G
dom
⁡
DProd
S
↔
G
∈
Grp
∧
S
:
dom
⁡
S
⟶
SubGrp
⁡
G
∧
∀
x
∈
dom
⁡
S
∀
y
∈
dom
⁡
S
∖
x
S
⁡
x
⊆
Cntz
⁡
G
⁡
S
⁡
y
∧
S
⁡
x
∩
mrCls
⁡
SubGrp
⁡
G
⁡
⋃
S
dom
⁡
S
∖
x
=
0
G
10
9
ibi
⊢
G
dom
⁡
DProd
S
→
G
∈
Grp
∧
S
:
dom
⁡
S
⟶
SubGrp
⁡
G
∧
∀
x
∈
dom
⁡
S
∀
y
∈
dom
⁡
S
∖
x
S
⁡
x
⊆
Cntz
⁡
G
⁡
S
⁡
y
∧
S
⁡
x
∩
mrCls
⁡
SubGrp
⁡
G
⁡
⋃
S
dom
⁡
S
∖
x
=
0
G
11
10
simp2d
⊢
G
dom
⁡
DProd
S
→
S
:
dom
⁡
S
⟶
SubGrp
⁡
G