| Step |
Hyp |
Ref |
Expression |
| 1 |
|
hstrlem3.1 |
|- S = ( x e. CH |-> ( ( projh ` x ) ` u ) ) |
| 2 |
|
hstrlem3.2 |
|- ( ph <-> ( u e. ( A \ B ) /\ ( normh ` u ) = 1 ) ) |
| 3 |
|
hstrlem3.3 |
|- A e. CH |
| 4 |
|
hstrlem3.4 |
|- B e. CH |
| 5 |
1
|
hstrlem2 |
|- ( B e. CH -> ( S ` B ) = ( ( projh ` B ) ` u ) ) |
| 6 |
5
|
fveq2d |
|- ( B e. CH -> ( normh ` ( S ` B ) ) = ( normh ` ( ( projh ` B ) ` u ) ) ) |
| 7 |
4 6
|
ax-mp |
|- ( normh ` ( S ` B ) ) = ( normh ` ( ( projh ` B ) ` u ) ) |
| 8 |
|
eldif |
|- ( u e. ( A \ B ) <-> ( u e. A /\ -. u e. B ) ) |
| 9 |
3
|
cheli |
|- ( u e. A -> u e. ~H ) |
| 10 |
|
pjnel |
|- ( ( B e. CH /\ u e. ~H ) -> ( -. u e. B <-> ( normh ` ( ( projh ` B ) ` u ) ) < ( normh ` u ) ) ) |
| 11 |
4 10
|
mpan |
|- ( u e. ~H -> ( -. u e. B <-> ( normh ` ( ( projh ` B ) ` u ) ) < ( normh ` u ) ) ) |
| 12 |
11
|
biimpa |
|- ( ( u e. ~H /\ -. u e. B ) -> ( normh ` ( ( projh ` B ) ` u ) ) < ( normh ` u ) ) |
| 13 |
9 12
|
sylan |
|- ( ( u e. A /\ -. u e. B ) -> ( normh ` ( ( projh ` B ) ` u ) ) < ( normh ` u ) ) |
| 14 |
8 13
|
sylbi |
|- ( u e. ( A \ B ) -> ( normh ` ( ( projh ` B ) ` u ) ) < ( normh ` u ) ) |
| 15 |
|
breq2 |
|- ( ( normh ` u ) = 1 -> ( ( normh ` ( ( projh ` B ) ` u ) ) < ( normh ` u ) <-> ( normh ` ( ( projh ` B ) ` u ) ) < 1 ) ) |
| 16 |
14 15
|
imbitrid |
|- ( ( normh ` u ) = 1 -> ( u e. ( A \ B ) -> ( normh ` ( ( projh ` B ) ` u ) ) < 1 ) ) |
| 17 |
16
|
impcom |
|- ( ( u e. ( A \ B ) /\ ( normh ` u ) = 1 ) -> ( normh ` ( ( projh ` B ) ` u ) ) < 1 ) |
| 18 |
7 17
|
eqbrtrid |
|- ( ( u e. ( A \ B ) /\ ( normh ` u ) = 1 ) -> ( normh ` ( S ` B ) ) < 1 ) |
| 19 |
2 18
|
sylbi |
|- ( ph -> ( normh ` ( S ` B ) ) < 1 ) |