Metamath Proof Explorer


Theorem cmbr3i

Description: Alternate definition for the commutes relation. Lemma 3 of Kalmbach p. 23. (Contributed by NM, 6-Dec-2000) (New usage is discouraged.)

Ref Expression
Hypotheses pjoml2.1 𝐴C
pjoml2.2 𝐵C
Assertion cmbr3i ( 𝐴 𝐶 𝐵 ↔ ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) )

Proof

Step Hyp Ref Expression
1 pjoml2.1 𝐴C
2 pjoml2.2 𝐵C
3 1 2 cmcmi ( 𝐴 𝐶 𝐵𝐵 𝐶 𝐴 )
4 2 1 cmbr2i ( 𝐵 𝐶 𝐴𝐵 = ( ( 𝐵 𝐴 ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) )
5 3 4 bitri ( 𝐴 𝐶 𝐵𝐵 = ( ( 𝐵 𝐴 ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) )
6 ineq2 ( 𝐵 = ( ( 𝐵 𝐴 ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) → ( 𝐴𝐵 ) = ( 𝐴 ∩ ( ( 𝐵 𝐴 ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) ) )
7 inass ( ( 𝐴 ∩ ( 𝐵 𝐴 ) ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) = ( 𝐴 ∩ ( ( 𝐵 𝐴 ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) )
8 2 1 chjcomi ( 𝐵 𝐴 ) = ( 𝐴 𝐵 )
9 8 ineq2i ( 𝐴 ∩ ( 𝐵 𝐴 ) ) = ( 𝐴 ∩ ( 𝐴 𝐵 ) )
10 1 2 chabs2i ( 𝐴 ∩ ( 𝐴 𝐵 ) ) = 𝐴
11 9 10 eqtri ( 𝐴 ∩ ( 𝐵 𝐴 ) ) = 𝐴
12 1 choccli ( ⊥ ‘ 𝐴 ) ∈ C
13 2 12 chjcomi ( 𝐵 ( ⊥ ‘ 𝐴 ) ) = ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 )
14 11 13 ineq12i ( ( 𝐴 ∩ ( 𝐵 𝐴 ) ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) = ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) )
15 7 14 eqtr3i ( 𝐴 ∩ ( ( 𝐵 𝐴 ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) ) = ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) )
16 6 15 eqtr2di ( 𝐵 = ( ( 𝐵 𝐴 ) ∩ ( 𝐵 ( ⊥ ‘ 𝐴 ) ) ) → ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) )
17 5 16 sylbi ( 𝐴 𝐶 𝐵 → ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) )
18 inss1 ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ⊆ 𝐴
19 2 choccli ( ⊥ ‘ 𝐵 ) ∈ C
20 1 19 chincli ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ∈ C
21 20 1 pjoml2i ( ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ⊆ 𝐴 → ( ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ∨ ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ) = 𝐴 )
22 18 21 ax-mp ( ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ∨ ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ) = 𝐴
23 20 choccli ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∈ C
24 23 1 chincli ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ∈ C
25 20 24 chjcomi ( ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ∨ ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ) = ( ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) )
26 22 25 eqtr3i 𝐴 = ( ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) )
27 1 2 chdmm3i ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) = ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 )
28 27 ineq2i ( 𝐴 ∩ ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ) = ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) )
29 incom ( 𝐴 ∩ ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ) = ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 )
30 28 29 eqtr3i ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 )
31 30 eqeq1i ( ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) ↔ ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) = ( 𝐴𝐵 ) )
32 oveq1 ( ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) = ( 𝐴𝐵 ) → ( ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) = ( ( 𝐴𝐵 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) )
33 31 32 sylbi ( ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) → ( ( ( ⊥ ‘ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) ∩ 𝐴 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) = ( ( 𝐴𝐵 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) )
34 26 33 eqtrid ( ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) → 𝐴 = ( ( 𝐴𝐵 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) )
35 1 2 cmbri ( 𝐴 𝐶 𝐵𝐴 = ( ( 𝐴𝐵 ) ∨ ( 𝐴 ∩ ( ⊥ ‘ 𝐵 ) ) ) )
36 34 35 sylibr ( ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) → 𝐴 𝐶 𝐵 )
37 17 36 impbii ( 𝐴 𝐶 𝐵 ↔ ( 𝐴 ∩ ( ( ⊥ ‘ 𝐴 ) ∨ 𝐵 ) ) = ( 𝐴𝐵 ) )