Metamath Proof Explorer


Theorem atabsi

Description: Absorption of an incomparable atom. Similar to Exercise 7.1 of MaedaMaeda p. 34. (Contributed by NM, 15-Jul-2004) (New usage is discouraged.)

Ref Expression
Hypotheses atabs.1 𝐴C
atabs.2 𝐵C
Assertion atabsi ( 𝐶 ∈ HAtoms → ( ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) → ( ( 𝐴 𝐶 ) ∩ 𝐵 ) = ( 𝐴𝐵 ) ) )

Proof

Step Hyp Ref Expression
1 atabs.1 𝐴C
2 atabs.2 𝐵C
3 inass ( ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) ∩ 𝐵 ) = ( ( 𝐴 𝐶 ) ∩ ( ( 𝐴 𝐵 ) ∩ 𝐵 ) )
4 1 2 chjcomi ( 𝐴 𝐵 ) = ( 𝐵 𝐴 )
5 4 ineq1i ( ( 𝐴 𝐵 ) ∩ 𝐵 ) = ( ( 𝐵 𝐴 ) ∩ 𝐵 )
6 incom ( ( 𝐵 𝐴 ) ∩ 𝐵 ) = ( 𝐵 ∩ ( 𝐵 𝐴 ) )
7 2 1 chabs2i ( 𝐵 ∩ ( 𝐵 𝐴 ) ) = 𝐵
8 5 6 7 3eqtri ( ( 𝐴 𝐵 ) ∩ 𝐵 ) = 𝐵
9 8 ineq2i ( ( 𝐴 𝐶 ) ∩ ( ( 𝐴 𝐵 ) ∩ 𝐵 ) ) = ( ( 𝐴 𝐶 ) ∩ 𝐵 )
10 3 9 eqtr2i ( ( 𝐴 𝐶 ) ∩ 𝐵 ) = ( ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) ∩ 𝐵 )
11 1 2 chub1i 𝐴 ⊆ ( 𝐴 𝐵 )
12 atelch ( 𝐶 ∈ HAtoms → 𝐶C )
13 1 2 chjcli ( 𝐴 𝐵 ) ∈ C
14 atmd ( ( 𝐶 ∈ HAtoms ∧ ( 𝐴 𝐵 ) ∈ C ) → 𝐶 𝑀 ( 𝐴 𝐵 ) )
15 13 14 mpan2 ( 𝐶 ∈ HAtoms → 𝐶 𝑀 ( 𝐴 𝐵 ) )
16 mdi ( ( ( 𝐶C ∧ ( 𝐴 𝐵 ) ∈ C𝐴C ) ∧ ( 𝐶 𝑀 ( 𝐴 𝐵 ) ∧ 𝐴 ⊆ ( 𝐴 𝐵 ) ) ) → ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) = ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) )
17 16 exp32 ( ( 𝐶C ∧ ( 𝐴 𝐵 ) ∈ C𝐴C ) → ( 𝐶 𝑀 ( 𝐴 𝐵 ) → ( 𝐴 ⊆ ( 𝐴 𝐵 ) → ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) = ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) ) ) )
18 13 1 17 mp3an23 ( 𝐶C → ( 𝐶 𝑀 ( 𝐴 𝐵 ) → ( 𝐴 ⊆ ( 𝐴 𝐵 ) → ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) = ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) ) ) )
19 12 15 18 sylc ( 𝐶 ∈ HAtoms → ( 𝐴 ⊆ ( 𝐴 𝐵 ) → ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) = ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) ) )
20 11 19 mpi ( 𝐶 ∈ HAtoms → ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) = ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) )
21 20 adantr ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) = ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) )
22 incom ( 𝐶 ∩ ( 𝐴 𝐵 ) ) = ( ( 𝐴 𝐵 ) ∩ 𝐶 )
23 atnssm0 ( ( ( 𝐴 𝐵 ) ∈ C𝐶 ∈ HAtoms ) → ( ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ↔ ( ( 𝐴 𝐵 ) ∩ 𝐶 ) = 0 ) )
24 13 23 mpan ( 𝐶 ∈ HAtoms → ( ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ↔ ( ( 𝐴 𝐵 ) ∩ 𝐶 ) = 0 ) )
25 24 biimpa ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( ( 𝐴 𝐵 ) ∩ 𝐶 ) = 0 )
26 22 25 eqtrid ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( 𝐶 ∩ ( 𝐴 𝐵 ) ) = 0 )
27 26 oveq2d ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) = ( 𝐴 0 ) )
28 1 chj0i ( 𝐴 0 ) = 𝐴
29 27 28 eqtrdi ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( 𝐴 ( 𝐶 ∩ ( 𝐴 𝐵 ) ) ) = 𝐴 )
30 21 29 eqtrd ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) = 𝐴 )
31 30 ineq1d ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( ( ( 𝐴 𝐶 ) ∩ ( 𝐴 𝐵 ) ) ∩ 𝐵 ) = ( 𝐴𝐵 ) )
32 10 31 eqtrid ( ( 𝐶 ∈ HAtoms ∧ ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) ) → ( ( 𝐴 𝐶 ) ∩ 𝐵 ) = ( 𝐴𝐵 ) )
33 32 ex ( 𝐶 ∈ HAtoms → ( ¬ 𝐶 ⊆ ( 𝐴 𝐵 ) → ( ( 𝐴 𝐶 ) ∩ 𝐵 ) = ( 𝐴𝐵 ) ) )