Metamath Proof Explorer


Theorem sdrgdrng

Description: A sub-division-ring is a division ring. (Contributed by SN, 19-Feb-2025)

Ref Expression
Hypothesis sdrgdrng.1 ⊢ S = R ↾ 𝑠 A
Assertion sdrgdrng ⊢ A ∈ SubDRing ⁡ R → S ∈ DivRing

Proof

Step Hyp Ref Expression
1 sdrgdrng.1 ⊢ S = R ↾ 𝑠 A
2 issdrg ⊢ A ∈ SubDRing ⁡ R ↔ R ∈ DivRing ∧ A ∈ SubRing ⁡ R ∧ R ↾ 𝑠 A ∈ DivRing
3 2 simp3bi ⊢ A ∈ SubDRing ⁡ R → R ↾ 𝑠 A ∈ DivRing
4 1 3 eqeltrid ⊢ A ∈ SubDRing ⁡ R → S ∈ DivRing