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Description: A principal ideal is nonzero iff it is generated by a nonzero elements (Contributed by Thierry Arnoux, 22-Mar-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | pidlnzb.1 | |- B = ( Base ` R ) |
|
| pidlnzb.2 | |- .0. = ( 0g ` R ) |
||
| pidlnzb.3 | |- K = ( RSpan ` R ) |
||
| Assertion | pidlnzb | |- ( ( R e. Ring /\ X e. B ) -> ( X =/= .0. <-> ( K ` { X } ) =/= { .0. } ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | pidlnzb.1 | |- B = ( Base ` R ) |
|
| 2 | pidlnzb.2 | |- .0. = ( 0g ` R ) |
|
| 3 | pidlnzb.3 | |- K = ( RSpan ` R ) |
|
| 4 | 1 2 3 | pidlnz | |- ( ( R e. Ring /\ X e. B /\ X =/= .0. ) -> ( K ` { X } ) =/= { .0. } ) |
| 5 | 4 | 3expa | |- ( ( ( R e. Ring /\ X e. B ) /\ X =/= .0. ) -> ( K ` { X } ) =/= { .0. } ) |
| 6 | sneq | |- ( X = .0. -> { X } = { .0. } ) |
|
| 7 | 6 | fveq2d | |- ( X = .0. -> ( K ` { X } ) = ( K ` { .0. } ) ) |
| 8 | 7 | adantl | |- ( ( ( R e. Ring /\ X e. B ) /\ X = .0. ) -> ( K ` { X } ) = ( K ` { .0. } ) ) |
| 9 | 3 2 | rsp0 | |- ( R e. Ring -> ( K ` { .0. } ) = { .0. } ) |
| 10 | 9 | ad2antrr | |- ( ( ( R e. Ring /\ X e. B ) /\ X = .0. ) -> ( K ` { .0. } ) = { .0. } ) |
| 11 | 8 10 | eqtrd | |- ( ( ( R e. Ring /\ X e. B ) /\ X = .0. ) -> ( K ` { X } ) = { .0. } ) |
| 12 | 11 | ex | |- ( ( R e. Ring /\ X e. B ) -> ( X = .0. -> ( K ` { X } ) = { .0. } ) ) |
| 13 | 12 | necon3d | |- ( ( R e. Ring /\ X e. B ) -> ( ( K ` { X } ) =/= { .0. } -> X =/= .0. ) ) |
| 14 | 13 | imp | |- ( ( ( R e. Ring /\ X e. B ) /\ ( K ` { X } ) =/= { .0. } ) -> X =/= .0. ) |
| 15 | 5 14 | impbida | |- ( ( R e. Ring /\ X e. B ) -> ( X =/= .0. <-> ( K ` { X } ) =/= { .0. } ) ) |