| Step |
Hyp |
Ref |
Expression |
| 1 |
|
eff |
|- exp : CC --> CC |
| 2 |
1
|
jctr |
|- ( S e. { RR , CC } -> ( S e. { RR , CC } /\ exp : CC --> CC ) ) |
| 3 |
|
recnprss |
|- ( S e. { RR , CC } -> S C_ CC ) |
| 4 |
|
dvef |
|- ( CC _D exp ) = exp |
| 5 |
4
|
dmeqi |
|- dom ( CC _D exp ) = dom exp |
| 6 |
1
|
fdmi |
|- dom exp = CC |
| 7 |
5 6
|
eqtri |
|- dom ( CC _D exp ) = CC |
| 8 |
3 7
|
sseqtrrdi |
|- ( S e. { RR , CC } -> S C_ dom ( CC _D exp ) ) |
| 9 |
|
ssid |
|- CC C_ CC |
| 10 |
8 9
|
jctil |
|- ( S e. { RR , CC } -> ( CC C_ CC /\ S C_ dom ( CC _D exp ) ) ) |
| 11 |
|
dvres3 |
|- ( ( ( S e. { RR , CC } /\ exp : CC --> CC ) /\ ( CC C_ CC /\ S C_ dom ( CC _D exp ) ) ) -> ( S _D ( exp |` S ) ) = ( ( CC _D exp ) |` S ) ) |
| 12 |
2 10 11
|
syl2anc |
|- ( S e. { RR , CC } -> ( S _D ( exp |` S ) ) = ( ( CC _D exp ) |` S ) ) |
| 13 |
4
|
reseq1i |
|- ( ( CC _D exp ) |` S ) = ( exp |` S ) |
| 14 |
12 13
|
eqtrdi |
|- ( S e. { RR , CC } -> ( S _D ( exp |` S ) ) = ( exp |` S ) ) |