Metamath Proof Explorer


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