Metamath Proof Explorer


Theorem hstrlem5

Description: Lemma for strong set of CH states theorem. (Contributed by NM, 30-Jun-2006) (New usage is discouraged.)

Ref Expression
Hypotheses hstrlem3.1 S = x C proj x u
hstrlem3.2 φ u A B norm u = 1
hstrlem3.3 A C
hstrlem3.4 B C
Assertion hstrlem5 φ norm S B < 1

Proof

Step Hyp Ref Expression
1 hstrlem3.1 S = x C proj x u
2 hstrlem3.2 φ u A B norm u = 1
3 hstrlem3.3 A C
4 hstrlem3.4 B C
5 1 hstrlem2 B C S B = proj B u
6 5 fveq2d B C norm S B = norm proj B u
7 4 6 ax-mp norm S B = norm proj B u
8 eldif u A B u A ¬ u B
9 3 cheli u A u
10 pjnel B C u ¬ u B norm proj B u < norm u
11 4 10 mpan u ¬ u B norm proj B u < norm u
12 11 biimpa u ¬ u B norm proj B u < norm u
13 9 12 sylan u A ¬ u B norm proj B u < norm u
14 8 13 sylbi u A B norm proj B u < norm u
15 breq2 norm u = 1 norm proj B u < norm u norm proj B u < 1
16 14 15 syl5ib norm u = 1 u A B norm proj B u < 1
17 16 impcom u A B norm u = 1 norm proj B u < 1
18 7 17 eqbrtrid u A B norm u = 1 norm S B < 1
19 2 18 sylbi φ norm S B < 1