Database
BASIC ALGEBRAIC STRUCTURES
Rings
Subrings
Subrings of non-unital rings
subrngmre
Next ⟩
subsubrng
Metamath Proof Explorer
Ascii
Unicode
Theorem
subrngmre
Description:
The subrings of a non-unital ring are a Moore system.
(Contributed by
AV
, 15-Feb-2025)
Ref
Expression
Hypothesis
subrngmre.b
⊢
B
=
Base
R
Assertion
subrngmre
⊢
R
∈
Rng
→
SubRng
⁡
R
∈
Moore
⁡
B
Proof
Step
Hyp
Ref
Expression
1
subrngmre.b
⊢
B
=
Base
R
2
1
subrngss
⊢
a
∈
SubRng
⁡
R
→
a
⊆
B
3
velpw
⊢
a
∈
𝒫
B
↔
a
⊆
B
4
2
3
sylibr
⊢
a
∈
SubRng
⁡
R
→
a
∈
𝒫
B
5
4
a1i
⊢
R
∈
Rng
→
a
∈
SubRng
⁡
R
→
a
∈
𝒫
B
6
5
ssrdv
⊢
R
∈
Rng
→
SubRng
⁡
R
⊆
𝒫
B
7
1
subrngid
⊢
R
∈
Rng
→
B
∈
SubRng
⁡
R
8
subrngint
⊢
a
⊆
SubRng
⁡
R
∧
a
≠
∅
→
⋂
a
∈
SubRng
⁡
R
9
8
3adant1
⊢
R
∈
Rng
∧
a
⊆
SubRng
⁡
R
∧
a
≠
∅
→
⋂
a
∈
SubRng
⁡
R
10
6
7
9
ismred
⊢
R
∈
Rng
→
SubRng
⁡
R
∈
Moore
⁡
B