Description: Reverse closure for a subring predicate. (Contributed by AV, 14-Feb-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | subrngrcl | ⊢ ( 𝐴 ∈ ( SubRng ‘ 𝑅 ) → 𝑅 ∈ Rng ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | eqid | ⊢ ( Base ‘ 𝑅 ) = ( Base ‘ 𝑅 ) | |
| 2 | 1 | issubrng | ⊢ ( 𝐴 ∈ ( SubRng ‘ 𝑅 ) ↔ ( 𝑅 ∈ Rng ∧ ( 𝑅 ↾s 𝐴 ) ∈ Rng ∧ 𝐴 ⊆ ( Base ‘ 𝑅 ) ) ) |
| 3 | 2 | simp1bi | ⊢ ( 𝐴 ∈ ( SubRng ‘ 𝑅 ) → 𝑅 ∈ Rng ) |