Description: Trivial groups are not simple. (Contributed by Rohan Ridenour, 3-Aug-2023)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | trivnsimpgd.1 | |- B = ( Base ` G ) | |
| trivnsimpgd.2 | |- .0. = ( 0g ` G ) | ||
| trivnsimpgd.3 | |- ( ph -> G e. Grp ) | ||
| trivnsimpgd.4 | |- ( ph -> B = { .0. } ) | ||
| Assertion | trivnsimpgd | |- ( ph -> -. G e. SimpGrp ) | 
| Step | Hyp | Ref | Expression | 
|---|---|---|---|
| 1 | trivnsimpgd.1 | |- B = ( Base ` G ) | |
| 2 | trivnsimpgd.2 | |- .0. = ( 0g ` G ) | |
| 3 | trivnsimpgd.3 | |- ( ph -> G e. Grp ) | |
| 4 | trivnsimpgd.4 |  |-  ( ph -> B = { .0. } ) | |
| 5 | snnen2o |  |-  -. { B } ~~ 2o | |
| 6 | 1 2 3 4 | trivnsgd |  |-  ( ph -> ( NrmSGrp ` G ) = { B } ) | 
| 7 | 6 | breq1d |  |-  ( ph -> ( ( NrmSGrp ` G ) ~~ 2o <-> { B } ~~ 2o ) ) | 
| 8 | 5 7 | mtbiri | |- ( ph -> -. ( NrmSGrp ` G ) ~~ 2o ) | 
| 9 | simpg2nsg | |- ( G e. SimpGrp -> ( NrmSGrp ` G ) ~~ 2o ) | |
| 10 | 8 9 | nsyl | |- ( ph -> -. G e. SimpGrp ) |