Metamath Proof Explorer


Theorem lcfrlem18

Description: Lemma for lcfr . (Contributed by NM, 24-Feb-2015)

Ref Expression
Hypotheses lcfrlem17.h 𝐻 = ( LHyp ‘ 𝐾 )
lcfrlem17.o = ( ( ocH ‘ 𝐾 ) ‘ 𝑊 )
lcfrlem17.u 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
lcfrlem17.v 𝑉 = ( Base ‘ 𝑈 )
lcfrlem17.p + = ( +g𝑈 )
lcfrlem17.z 0 = ( 0g𝑈 )
lcfrlem17.n 𝑁 = ( LSpan ‘ 𝑈 )
lcfrlem17.a 𝐴 = ( LSAtoms ‘ 𝑈 )
lcfrlem17.k ( 𝜑 → ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) )
lcfrlem17.x ( 𝜑𝑋 ∈ ( 𝑉 ∖ { 0 } ) )
lcfrlem17.y ( 𝜑𝑌 ∈ ( 𝑉 ∖ { 0 } ) )
lcfrlem17.ne ( 𝜑 → ( 𝑁 ‘ { 𝑋 } ) ≠ ( 𝑁 ‘ { 𝑌 } ) )
Assertion lcfrlem18 ( 𝜑 → ( ‘ { 𝑋 , 𝑌 } ) = ( ( ‘ { 𝑋 } ) ∩ ( ‘ { 𝑌 } ) ) )

Proof

Step Hyp Ref Expression
1 lcfrlem17.h 𝐻 = ( LHyp ‘ 𝐾 )
2 lcfrlem17.o = ( ( ocH ‘ 𝐾 ) ‘ 𝑊 )
3 lcfrlem17.u 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
4 lcfrlem17.v 𝑉 = ( Base ‘ 𝑈 )
5 lcfrlem17.p + = ( +g𝑈 )
6 lcfrlem17.z 0 = ( 0g𝑈 )
7 lcfrlem17.n 𝑁 = ( LSpan ‘ 𝑈 )
8 lcfrlem17.a 𝐴 = ( LSAtoms ‘ 𝑈 )
9 lcfrlem17.k ( 𝜑 → ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) )
10 lcfrlem17.x ( 𝜑𝑋 ∈ ( 𝑉 ∖ { 0 } ) )
11 lcfrlem17.y ( 𝜑𝑌 ∈ ( 𝑉 ∖ { 0 } ) )
12 lcfrlem17.ne ( 𝜑 → ( 𝑁 ‘ { 𝑋 } ) ≠ ( 𝑁 ‘ { 𝑌 } ) )
13 df-pr { 𝑋 , 𝑌 } = ( { 𝑋 } ∪ { 𝑌 } )
14 13 fveq2i ( ‘ { 𝑋 , 𝑌 } ) = ( ‘ ( { 𝑋 } ∪ { 𝑌 } ) )
15 10 eldifad ( 𝜑𝑋𝑉 )
16 15 snssd ( 𝜑 → { 𝑋 } ⊆ 𝑉 )
17 11 eldifad ( 𝜑𝑌𝑉 )
18 17 snssd ( 𝜑 → { 𝑌 } ⊆ 𝑉 )
19 1 3 4 2 dochdmj1 ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ { 𝑋 } ⊆ 𝑉 ∧ { 𝑌 } ⊆ 𝑉 ) → ( ‘ ( { 𝑋 } ∪ { 𝑌 } ) ) = ( ( ‘ { 𝑋 } ) ∩ ( ‘ { 𝑌 } ) ) )
20 9 16 18 19 syl3anc ( 𝜑 → ( ‘ ( { 𝑋 } ∪ { 𝑌 } ) ) = ( ( ‘ { 𝑋 } ) ∩ ( ‘ { 𝑌 } ) ) )
21 14 20 syl5eq ( 𝜑 → ( ‘ { 𝑋 , 𝑌 } ) = ( ( ‘ { 𝑋 } ) ∩ ( ‘ { 𝑌 } ) ) )