Description: A group element's inverse is a group element. (Contributed by SN, 29-Jan-2025)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | grpinvcld.b | |- B = ( Base ` G ) |
|
| grpinvcld.n | |- N = ( invg ` G ) |
||
| grpinvcld.g | |- ( ph -> G e. Grp ) |
||
| grpinvcld.1 | |- ( ph -> X e. B ) |
||
| Assertion | grpinvcld | |- ( ph -> ( N ` X ) e. B ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | grpinvcld.b | |- B = ( Base ` G ) |
|
| 2 | grpinvcld.n | |- N = ( invg ` G ) |
|
| 3 | grpinvcld.g | |- ( ph -> G e. Grp ) |
|
| 4 | grpinvcld.1 | |- ( ph -> X e. B ) |
|
| 5 | 1 2 | grpinvcl | |- ( ( G e. Grp /\ X e. B ) -> ( N ` X ) e. B ) |
| 6 | 3 4 5 | syl2anc | |- ( ph -> ( N ` X ) e. B ) |