Description: Reverse closure for a sub-division-ring predicate. (Contributed by SN, 19-Feb-2025)
| Ref | Expression | ||
|---|---|---|---|
| Assertion | sdrgrcl | |- ( A e. ( SubDRing ` R ) -> R e. DivRing ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | issdrg | |- ( A e. ( SubDRing ` R ) <-> ( R e. DivRing /\ A e. ( SubRing ` R ) /\ ( R |`s A ) e. DivRing ) ) |
|
| 2 | 1 | simp1bi | |- ( A e. ( SubDRing ` R ) -> R e. DivRing ) |