Step |
Hyp |
Ref |
Expression |
1 |
|
pgrpsubgsymgbi.g |
|- G = ( SymGrp ` A ) |
2 |
|
pgrpsubgsymgbi.b |
|- B = ( Base ` G ) |
3 |
2
|
issubg |
|- ( P e. ( SubGrp ` G ) <-> ( G e. Grp /\ P C_ B /\ ( G |`s P ) e. Grp ) ) |
4 |
|
3anass |
|- ( ( G e. Grp /\ P C_ B /\ ( G |`s P ) e. Grp ) <-> ( G e. Grp /\ ( P C_ B /\ ( G |`s P ) e. Grp ) ) ) |
5 |
3 4
|
bitri |
|- ( P e. ( SubGrp ` G ) <-> ( G e. Grp /\ ( P C_ B /\ ( G |`s P ) e. Grp ) ) ) |
6 |
1
|
symggrp |
|- ( A e. V -> G e. Grp ) |
7 |
|
ibar |
|- ( G e. Grp -> ( ( P C_ B /\ ( G |`s P ) e. Grp ) <-> ( G e. Grp /\ ( P C_ B /\ ( G |`s P ) e. Grp ) ) ) ) |
8 |
7
|
bicomd |
|- ( G e. Grp -> ( ( G e. Grp /\ ( P C_ B /\ ( G |`s P ) e. Grp ) ) <-> ( P C_ B /\ ( G |`s P ) e. Grp ) ) ) |
9 |
6 8
|
syl |
|- ( A e. V -> ( ( G e. Grp /\ ( P C_ B /\ ( G |`s P ) e. Grp ) ) <-> ( P C_ B /\ ( G |`s P ) e. Grp ) ) ) |
10 |
5 9
|
syl5bb |
|- ( A e. V -> ( P e. ( SubGrp ` G ) <-> ( P C_ B /\ ( G |`s P ) e. Grp ) ) ) |