Description: Reverse closure for a sub-division-ring predicate. (Contributed by SN, 19-Feb-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | sdrgrcl | ⊢ ( 𝐴 ∈ ( SubDRing ‘ 𝑅 ) → 𝑅 ∈ DivRing ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | issdrg | ⊢ ( 𝐴 ∈ ( SubDRing ‘ 𝑅 ) ↔ ( 𝑅 ∈ DivRing ∧ 𝐴 ∈ ( SubRing ‘ 𝑅 ) ∧ ( 𝑅 ↾s 𝐴 ) ∈ DivRing ) ) | |
| 2 | 1 | simp1bi | ⊢ ( 𝐴 ∈ ( SubDRing ‘ 𝑅 ) → 𝑅 ∈ DivRing ) |