Metamath Proof Explorer


Theorem strlem1

Description: Lemma for strong state theorem: if closed subspace A is not contained in B , there is a unit vector u in their difference. (Contributed by NM, 25-Oct-1999) (New usage is discouraged.)

Ref Expression
Hypotheses strlem1.1 A C
strlem1.2 B C
Assertion strlem1 ¬ A B u A B norm u = 1

Proof

Step Hyp Ref Expression
1 strlem1.1 A C
2 strlem1.2 B C
3 neq0 ¬ A B = x x A B
4 ssdif0 A B A B =
5 3 4 xchnxbir ¬ A B x x A B
6 eldifi x A B x A
7 1 cheli x A x
8 normcl x norm x
9 6 7 8 3syl x A B norm x
10 ch0 B C 0 B
11 2 10 ax-mp 0 B
12 eldifn 0 A B ¬ 0 B
13 11 12 mt2 ¬ 0 A B
14 eleq1 x = 0 x A B 0 A B
15 13 14 mtbiri x = 0 ¬ x A B
16 15 con2i x A B ¬ x = 0
17 norm-i x norm x = 0 x = 0
18 6 7 17 3syl x A B norm x = 0 x = 0
19 16 18 mtbird x A B ¬ norm x = 0
20 19 neqned x A B norm x 0
21 9 20 rereccld x A B 1 norm x
22 21 recnd x A B 1 norm x
23 1 chshii A S
24 shmulcl A S 1 norm x x A 1 norm x x A
25 23 24 mp3an1 1 norm x x A 1 norm x x A
26 25 ex 1 norm x x A 1 norm x x A
27 22 26 syl x A B x A 1 norm x x A
28 9 recnd x A B norm x
29 2 chshii B S
30 shmulcl B S norm x 1 norm x x B norm x 1 norm x x B
31 29 30 mp3an1 norm x 1 norm x x B norm x 1 norm x x B
32 31 ex norm x 1 norm x x B norm x 1 norm x x B
33 28 32 syl x A B 1 norm x x B norm x 1 norm x x B
34 28 20 recidd x A B norm x 1 norm x = 1
35 34 oveq1d x A B norm x 1 norm x x = 1 x
36 6 7 syl x A B x
37 ax-hvmulass norm x 1 norm x x norm x 1 norm x x = norm x 1 norm x x
38 28 22 36 37 syl3anc x A B norm x 1 norm x x = norm x 1 norm x x
39 ax-hvmulid x 1 x = x
40 6 7 39 3syl x A B 1 x = x
41 35 38 40 3eqtr3d x A B norm x 1 norm x x = x
42 41 eleq1d x A B norm x 1 norm x x B x B
43 33 42 sylibd x A B 1 norm x x B x B
44 43 con3d x A B ¬ x B ¬ 1 norm x x B
45 27 44 anim12d x A B x A ¬ x B 1 norm x x A ¬ 1 norm x x B
46 eldif x A B x A ¬ x B
47 eldif 1 norm x x A B 1 norm x x A ¬ 1 norm x x B
48 45 46 47 3imtr4g x A B x A B 1 norm x x A B
49 48 pm2.43i x A B 1 norm x x A B
50 norm-iii 1 norm x x norm 1 norm x x = 1 norm x norm x
51 22 36 50 syl2anc x A B norm 1 norm x x = 1 norm x norm x
52 15 necon2ai x A B x 0
53 normgt0 x x 0 0 < norm x
54 6 7 53 3syl x A B x 0 0 < norm x
55 52 54 mpbid x A B 0 < norm x
56 1re 1
57 0le1 0 1
58 divge0 1 0 1 norm x 0 < norm x 0 1 norm x
59 56 57 58 mpanl12 norm x 0 < norm x 0 1 norm x
60 9 55 59 syl2anc x A B 0 1 norm x
61 21 60 absidd x A B 1 norm x = 1 norm x
62 61 oveq1d x A B 1 norm x norm x = 1 norm x norm x
63 28 20 recid2d x A B 1 norm x norm x = 1
64 51 62 63 3eqtrd x A B norm 1 norm x x = 1
65 fveqeq2 u = 1 norm x x norm u = 1 norm 1 norm x x = 1
66 65 rspcev 1 norm x x A B norm 1 norm x x = 1 u A B norm u = 1
67 49 64 66 syl2anc x A B u A B norm u = 1
68 67 exlimiv x x A B u A B norm u = 1
69 5 68 sylbi ¬ A B u A B norm u = 1