Step |
Hyp |
Ref |
Expression |
1 |
|
dprdf1.1 |
|- ( ph -> G dom DProd S ) |
2 |
|
dprdf1.2 |
|- ( ph -> dom S = I ) |
3 |
|
dprdf1.3 |
|- ( ph -> F : J -1-1-> I ) |
4 |
|
f1f |
|- ( F : J -1-1-> I -> F : J --> I ) |
5 |
|
frn |
|- ( F : J --> I -> ran F C_ I ) |
6 |
3 4 5
|
3syl |
|- ( ph -> ran F C_ I ) |
7 |
1 2 6
|
dprdres |
|- ( ph -> ( G dom DProd ( S |` ran F ) /\ ( G DProd ( S |` ran F ) ) C_ ( G DProd S ) ) ) |
8 |
7
|
simpld |
|- ( ph -> G dom DProd ( S |` ran F ) ) |
9 |
1 2
|
dprdf2 |
|- ( ph -> S : I --> ( SubGrp ` G ) ) |
10 |
9 6
|
fssresd |
|- ( ph -> ( S |` ran F ) : ran F --> ( SubGrp ` G ) ) |
11 |
10
|
fdmd |
|- ( ph -> dom ( S |` ran F ) = ran F ) |
12 |
|
f1f1orn |
|- ( F : J -1-1-> I -> F : J -1-1-onto-> ran F ) |
13 |
3 12
|
syl |
|- ( ph -> F : J -1-1-onto-> ran F ) |
14 |
8 11 13
|
dprdf1o |
|- ( ph -> ( G dom DProd ( ( S |` ran F ) o. F ) /\ ( G DProd ( ( S |` ran F ) o. F ) ) = ( G DProd ( S |` ran F ) ) ) ) |
15 |
14
|
simpld |
|- ( ph -> G dom DProd ( ( S |` ran F ) o. F ) ) |
16 |
|
ssid |
|- ran F C_ ran F |
17 |
|
cores |
|- ( ran F C_ ran F -> ( ( S |` ran F ) o. F ) = ( S o. F ) ) |
18 |
16 17
|
ax-mp |
|- ( ( S |` ran F ) o. F ) = ( S o. F ) |
19 |
15 18
|
breqtrdi |
|- ( ph -> G dom DProd ( S o. F ) ) |
20 |
18
|
oveq2i |
|- ( G DProd ( ( S |` ran F ) o. F ) ) = ( G DProd ( S o. F ) ) |
21 |
14
|
simprd |
|- ( ph -> ( G DProd ( ( S |` ran F ) o. F ) ) = ( G DProd ( S |` ran F ) ) ) |
22 |
20 21
|
eqtr3id |
|- ( ph -> ( G DProd ( S o. F ) ) = ( G DProd ( S |` ran F ) ) ) |
23 |
7
|
simprd |
|- ( ph -> ( G DProd ( S |` ran F ) ) C_ ( G DProd S ) ) |
24 |
22 23
|
eqsstrd |
|- ( ph -> ( G DProd ( S o. F ) ) C_ ( G DProd S ) ) |
25 |
19 24
|
jca |
|- ( ph -> ( G dom DProd ( S o. F ) /\ ( G DProd ( S o. F ) ) C_ ( G DProd S ) ) ) |