| Step |
Hyp |
Ref |
Expression |
| 1 |
|
pjima.1 |
|- A e. SH |
| 2 |
|
pjima.2 |
|- B e. CH |
| 3 |
1
|
sheli |
|- ( v e. A -> v e. ~H ) |
| 4 |
|
pjeq |
|- ( ( B e. CH /\ v e. ~H ) -> ( ( ( projh ` B ) ` v ) = u <-> ( u e. B /\ E. w e. ( _|_ ` B ) v = ( u +h w ) ) ) ) |
| 5 |
2 3 4
|
sylancr |
|- ( v e. A -> ( ( ( projh ` B ) ` v ) = u <-> ( u e. B /\ E. w e. ( _|_ ` B ) v = ( u +h w ) ) ) ) |
| 6 |
|
ibar |
|- ( u e. B -> ( E. w e. ( _|_ ` B ) v = ( u +h w ) <-> ( u e. B /\ E. w e. ( _|_ ` B ) v = ( u +h w ) ) ) ) |
| 7 |
6
|
bicomd |
|- ( u e. B -> ( ( u e. B /\ E. w e. ( _|_ ` B ) v = ( u +h w ) ) <-> E. w e. ( _|_ ` B ) v = ( u +h w ) ) ) |
| 8 |
5 7
|
sylan9bbr |
|- ( ( u e. B /\ v e. A ) -> ( ( ( projh ` B ) ` v ) = u <-> E. w e. ( _|_ ` B ) v = ( u +h w ) ) ) |
| 9 |
2
|
cheli |
|- ( u e. B -> u e. ~H ) |
| 10 |
2
|
choccli |
|- ( _|_ ` B ) e. CH |
| 11 |
10
|
cheli |
|- ( w e. ( _|_ ` B ) -> w e. ~H ) |
| 12 |
|
hvsubadd |
|- ( ( v e. ~H /\ w e. ~H /\ u e. ~H ) -> ( ( v -h w ) = u <-> ( w +h u ) = v ) ) |
| 13 |
12
|
3comr |
|- ( ( u e. ~H /\ v e. ~H /\ w e. ~H ) -> ( ( v -h w ) = u <-> ( w +h u ) = v ) ) |
| 14 |
|
ax-hvcom |
|- ( ( u e. ~H /\ w e. ~H ) -> ( u +h w ) = ( w +h u ) ) |
| 15 |
14
|
3adant2 |
|- ( ( u e. ~H /\ v e. ~H /\ w e. ~H ) -> ( u +h w ) = ( w +h u ) ) |
| 16 |
15
|
eqeq1d |
|- ( ( u e. ~H /\ v e. ~H /\ w e. ~H ) -> ( ( u +h w ) = v <-> ( w +h u ) = v ) ) |
| 17 |
13 16
|
bitr4d |
|- ( ( u e. ~H /\ v e. ~H /\ w e. ~H ) -> ( ( v -h w ) = u <-> ( u +h w ) = v ) ) |
| 18 |
9 3 11 17
|
syl3an |
|- ( ( u e. B /\ v e. A /\ w e. ( _|_ ` B ) ) -> ( ( v -h w ) = u <-> ( u +h w ) = v ) ) |
| 19 |
|
eqcom |
|- ( u = ( v -h w ) <-> ( v -h w ) = u ) |
| 20 |
|
eqcom |
|- ( v = ( u +h w ) <-> ( u +h w ) = v ) |
| 21 |
18 19 20
|
3bitr4g |
|- ( ( u e. B /\ v e. A /\ w e. ( _|_ ` B ) ) -> ( u = ( v -h w ) <-> v = ( u +h w ) ) ) |
| 22 |
21
|
3expa |
|- ( ( ( u e. B /\ v e. A ) /\ w e. ( _|_ ` B ) ) -> ( u = ( v -h w ) <-> v = ( u +h w ) ) ) |
| 23 |
22
|
rexbidva |
|- ( ( u e. B /\ v e. A ) -> ( E. w e. ( _|_ ` B ) u = ( v -h w ) <-> E. w e. ( _|_ ` B ) v = ( u +h w ) ) ) |
| 24 |
8 23
|
bitr4d |
|- ( ( u e. B /\ v e. A ) -> ( ( ( projh ` B ) ` v ) = u <-> E. w e. ( _|_ ` B ) u = ( v -h w ) ) ) |
| 25 |
24
|
rexbidva |
|- ( u e. B -> ( E. v e. A ( ( projh ` B ) ` v ) = u <-> E. v e. A E. w e. ( _|_ ` B ) u = ( v -h w ) ) ) |
| 26 |
2
|
pjfni |
|- ( projh ` B ) Fn ~H |
| 27 |
1
|
shssii |
|- A C_ ~H |
| 28 |
|
fvelimab |
|- ( ( ( projh ` B ) Fn ~H /\ A C_ ~H ) -> ( u e. ( ( projh ` B ) " A ) <-> E. v e. A ( ( projh ` B ) ` v ) = u ) ) |
| 29 |
26 27 28
|
mp2an |
|- ( u e. ( ( projh ` B ) " A ) <-> E. v e. A ( ( projh ` B ) ` v ) = u ) |
| 30 |
10
|
chshii |
|- ( _|_ ` B ) e. SH |
| 31 |
|
shsel3 |
|- ( ( A e. SH /\ ( _|_ ` B ) e. SH ) -> ( u e. ( A +H ( _|_ ` B ) ) <-> E. v e. A E. w e. ( _|_ ` B ) u = ( v -h w ) ) ) |
| 32 |
1 30 31
|
mp2an |
|- ( u e. ( A +H ( _|_ ` B ) ) <-> E. v e. A E. w e. ( _|_ ` B ) u = ( v -h w ) ) |
| 33 |
25 29 32
|
3bitr4g |
|- ( u e. B -> ( u e. ( ( projh ` B ) " A ) <-> u e. ( A +H ( _|_ ` B ) ) ) ) |
| 34 |
33
|
pm5.32ri |
|- ( ( u e. ( ( projh ` B ) " A ) /\ u e. B ) <-> ( u e. ( A +H ( _|_ ` B ) ) /\ u e. B ) ) |
| 35 |
|
imassrn |
|- ( ( projh ` B ) " A ) C_ ran ( projh ` B ) |
| 36 |
2
|
pjrni |
|- ran ( projh ` B ) = B |
| 37 |
35 36
|
sseqtri |
|- ( ( projh ` B ) " A ) C_ B |
| 38 |
37
|
sseli |
|- ( u e. ( ( projh ` B ) " A ) -> u e. B ) |
| 39 |
38
|
pm4.71i |
|- ( u e. ( ( projh ` B ) " A ) <-> ( u e. ( ( projh ` B ) " A ) /\ u e. B ) ) |
| 40 |
|
elin |
|- ( u e. ( ( A +H ( _|_ ` B ) ) i^i B ) <-> ( u e. ( A +H ( _|_ ` B ) ) /\ u e. B ) ) |
| 41 |
34 39 40
|
3bitr4i |
|- ( u e. ( ( projh ` B ) " A ) <-> u e. ( ( A +H ( _|_ ` B ) ) i^i B ) ) |
| 42 |
41
|
eqriv |
|- ( ( projh ` B ) " A ) = ( ( A +H ( _|_ ` B ) ) i^i B ) |