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Description: A ring is nonzero if it has a nonzero element. (Contributed by Stefan O'Rear, 6-Feb-2015) (Revised by Mario Carneiro, 13-Jun-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ringelnzr.z | |- .0. = ( 0g ` R ) |
|
| ringelnzr.b | |- B = ( Base ` R ) |
||
| Assertion | ringelnzr | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> R e. NzRing ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ringelnzr.z | |- .0. = ( 0g ` R ) |
|
| 2 | ringelnzr.b | |- B = ( Base ` R ) |
|
| 3 | simpl | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> R e. Ring ) |
|
| 4 | eldifsni | |- ( X e. ( B \ { .0. } ) -> X =/= .0. ) |
|
| 5 | 4 | adantl | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> X =/= .0. ) |
| 6 | eldifi | |- ( X e. ( B \ { .0. } ) -> X e. B ) |
|
| 7 | 6 | adantl | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> X e. B ) |
| 8 | 2 1 | ring0cl | |- ( R e. Ring -> .0. e. B ) |
| 9 | 8 | adantr | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> .0. e. B ) |
| 10 | eqid | |- ( 1r ` R ) = ( 1r ` R ) |
|
| 11 | 2 10 1 | ring1eq0 | |- ( ( R e. Ring /\ X e. B /\ .0. e. B ) -> ( ( 1r ` R ) = .0. -> X = .0. ) ) |
| 12 | 3 7 9 11 | syl3anc | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> ( ( 1r ` R ) = .0. -> X = .0. ) ) |
| 13 | 12 | necon3d | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> ( X =/= .0. -> ( 1r ` R ) =/= .0. ) ) |
| 14 | 5 13 | mpd | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> ( 1r ` R ) =/= .0. ) |
| 15 | 10 1 | isnzr | |- ( R e. NzRing <-> ( R e. Ring /\ ( 1r ` R ) =/= .0. ) ) |
| 16 | 3 14 15 | sylanbrc | |- ( ( R e. Ring /\ X e. ( B \ { .0. } ) ) -> R e. NzRing ) |