Step |
Hyp |
Ref |
Expression |
1 |
|
lcvnbtwn.s |
|- S = ( LSubSp ` W ) |
2 |
|
lcvnbtwn.c |
|- C = (
|
3 |
|
lcvnbtwn.w |
|- ( ph -> W e. X ) |
4 |
|
lcvnbtwn.r |
|- ( ph -> R e. S ) |
5 |
|
lcvnbtwn.t |
|- ( ph -> T e. S ) |
6 |
|
lcvnbtwn.u |
|- ( ph -> U e. S ) |
7 |
|
lcvnbtwn.d |
|- ( ph -> R C T ) |
8 |
1 2 3 4 5
|
lcvbr |
|- ( ph -> ( R C T <-> ( R C. T /\ -. E. u e. S ( R C. u /\ u C. T ) ) ) ) |
9 |
7 8
|
mpbid |
|- ( ph -> ( R C. T /\ -. E. u e. S ( R C. u /\ u C. T ) ) ) |
10 |
9
|
simprd |
|- ( ph -> -. E. u e. S ( R C. u /\ u C. T ) ) |
11 |
|
psseq2 |
|- ( u = U -> ( R C. u <-> R C. U ) ) |
12 |
|
psseq1 |
|- ( u = U -> ( u C. T <-> U C. T ) ) |
13 |
11 12
|
anbi12d |
|- ( u = U -> ( ( R C. u /\ u C. T ) <-> ( R C. U /\ U C. T ) ) ) |
14 |
13
|
rspcev |
|- ( ( U e. S /\ ( R C. U /\ U C. T ) ) -> E. u e. S ( R C. u /\ u C. T ) ) |
15 |
6 14
|
sylan |
|- ( ( ph /\ ( R C. U /\ U C. T ) ) -> E. u e. S ( R C. u /\ u C. T ) ) |
16 |
10 15
|
mtand |
|- ( ph -> -. ( R C. U /\ U C. T ) ) |