Metamath Proof Explorer


Theorem atcv1

Description: Two atoms covering the zero subspace are equal. (Contributed by NM, 26-Jun-2004) (New usage is discouraged.)

Ref Expression
Assertion atcv1 ( ( ( 𝐴C𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) ∧ 𝐴 ( 𝐵 𝐶 ) ) → ( 𝐴 = 0𝐵 = 𝐶 ) )

Proof

Step Hyp Ref Expression
1 breq1 ( 𝐴 = 0 → ( 𝐴 ( 𝐵 𝐶 ) ↔ 0 ( 𝐵 𝐶 ) ) )
2 atcv0eq ( ( 𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) → ( 0 ( 𝐵 𝐶 ) ↔ 𝐵 = 𝐶 ) )
3 1 2 sylan9bbr ( ( ( 𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) ∧ 𝐴 = 0 ) → ( 𝐴 ( 𝐵 𝐶 ) ↔ 𝐵 = 𝐶 ) )
4 3 biimpd ( ( ( 𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) ∧ 𝐴 = 0 ) → ( 𝐴 ( 𝐵 𝐶 ) → 𝐵 = 𝐶 ) )
5 4 ex ( ( 𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) → ( 𝐴 = 0 → ( 𝐴 ( 𝐵 𝐶 ) → 𝐵 = 𝐶 ) ) )
6 5 com23 ( ( 𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) → ( 𝐴 ( 𝐵 𝐶 ) → ( 𝐴 = 0𝐵 = 𝐶 ) ) )
7 6 3adant1 ( ( 𝐴C𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) → ( 𝐴 ( 𝐵 𝐶 ) → ( 𝐴 = 0𝐵 = 𝐶 ) ) )
8 7 imp ( ( ( 𝐴C𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) ∧ 𝐴 ( 𝐵 𝐶 ) ) → ( 𝐴 = 0𝐵 = 𝐶 ) )
9 oveq1 ( 𝐵 = 𝐶 → ( 𝐵 𝐶 ) = ( 𝐶 𝐶 ) )
10 atelch ( 𝐶 ∈ HAtoms → 𝐶C )
11 chjidm ( 𝐶C → ( 𝐶 𝐶 ) = 𝐶 )
12 10 11 syl ( 𝐶 ∈ HAtoms → ( 𝐶 𝐶 ) = 𝐶 )
13 9 12 sylan9eq ( ( 𝐵 = 𝐶𝐶 ∈ HAtoms ) → ( 𝐵 𝐶 ) = 𝐶 )
14 13 eqcomd ( ( 𝐵 = 𝐶𝐶 ∈ HAtoms ) → 𝐶 = ( 𝐵 𝐶 ) )
15 14 eleq1d ( ( 𝐵 = 𝐶𝐶 ∈ HAtoms ) → ( 𝐶 ∈ HAtoms ↔ ( 𝐵 𝐶 ) ∈ HAtoms ) )
16 15 ex ( 𝐵 = 𝐶 → ( 𝐶 ∈ HAtoms → ( 𝐶 ∈ HAtoms ↔ ( 𝐵 𝐶 ) ∈ HAtoms ) ) )
17 16 ibd ( 𝐵 = 𝐶 → ( 𝐶 ∈ HAtoms → ( 𝐵 𝐶 ) ∈ HAtoms ) )
18 17 impcom ( ( 𝐶 ∈ HAtoms ∧ 𝐵 = 𝐶 ) → ( 𝐵 𝐶 ) ∈ HAtoms )
19 atcveq0 ( ( 𝐴C ∧ ( 𝐵 𝐶 ) ∈ HAtoms ) → ( 𝐴 ( 𝐵 𝐶 ) ↔ 𝐴 = 0 ) )
20 18 19 sylan2 ( ( 𝐴C ∧ ( 𝐶 ∈ HAtoms ∧ 𝐵 = 𝐶 ) ) → ( 𝐴 ( 𝐵 𝐶 ) ↔ 𝐴 = 0 ) )
21 20 biimpd ( ( 𝐴C ∧ ( 𝐶 ∈ HAtoms ∧ 𝐵 = 𝐶 ) ) → ( 𝐴 ( 𝐵 𝐶 ) → 𝐴 = 0 ) )
22 21 exp32 ( 𝐴C → ( 𝐶 ∈ HAtoms → ( 𝐵 = 𝐶 → ( 𝐴 ( 𝐵 𝐶 ) → 𝐴 = 0 ) ) ) )
23 22 com34 ( 𝐴C → ( 𝐶 ∈ HAtoms → ( 𝐴 ( 𝐵 𝐶 ) → ( 𝐵 = 𝐶𝐴 = 0 ) ) ) )
24 23 imp ( ( 𝐴C𝐶 ∈ HAtoms ) → ( 𝐴 ( 𝐵 𝐶 ) → ( 𝐵 = 𝐶𝐴 = 0 ) ) )
25 24 3adant2 ( ( 𝐴C𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) → ( 𝐴 ( 𝐵 𝐶 ) → ( 𝐵 = 𝐶𝐴 = 0 ) ) )
26 25 imp ( ( ( 𝐴C𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) ∧ 𝐴 ( 𝐵 𝐶 ) ) → ( 𝐵 = 𝐶𝐴 = 0 ) )
27 8 26 impbid ( ( ( 𝐴C𝐵 ∈ HAtoms ∧ 𝐶 ∈ HAtoms ) ∧ 𝐴 ( 𝐵 𝐶 ) ) → ( 𝐴 = 0𝐵 = 𝐶 ) )