Metamath Proof Explorer


Theorem djhval

Description: Subspace join for DVecH vector space. (Contributed by NM, 19-Jul-2014)

Ref Expression
Hypotheses djhval.h 𝐻 = ( LHyp ‘ 𝐾 )
djhval.u 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
djhval.v 𝑉 = ( Base ‘ 𝑈 )
djhval.o = ( ( ocH ‘ 𝐾 ) ‘ 𝑊 )
djhval.j = ( ( joinH ‘ 𝐾 ) ‘ 𝑊 )
Assertion djhval ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → ( 𝑋 𝑌 ) = ( ‘ ( ( 𝑋 ) ∩ ( 𝑌 ) ) ) )

Proof

Step Hyp Ref Expression
1 djhval.h 𝐻 = ( LHyp ‘ 𝐾 )
2 djhval.u 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
3 djhval.v 𝑉 = ( Base ‘ 𝑈 )
4 djhval.o = ( ( ocH ‘ 𝐾 ) ‘ 𝑊 )
5 djhval.j = ( ( joinH ‘ 𝐾 ) ‘ 𝑊 )
6 1 2 3 4 5 djhfval ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) → = ( 𝑥 ∈ 𝒫 𝑉 , 𝑦 ∈ 𝒫 𝑉 ↦ ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) ) )
7 6 adantr ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → = ( 𝑥 ∈ 𝒫 𝑉 , 𝑦 ∈ 𝒫 𝑉 ↦ ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) ) )
8 7 oveqd ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → ( 𝑋 𝑌 ) = ( 𝑋 ( 𝑥 ∈ 𝒫 𝑉 , 𝑦 ∈ 𝒫 𝑉 ↦ ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) ) 𝑌 ) )
9 3 fvexi 𝑉 ∈ V
10 9 elpw2 ( 𝑋 ∈ 𝒫 𝑉𝑋𝑉 )
11 10 biimpri ( 𝑋𝑉𝑋 ∈ 𝒫 𝑉 )
12 11 ad2antrl ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → 𝑋 ∈ 𝒫 𝑉 )
13 9 elpw2 ( 𝑌 ∈ 𝒫 𝑉𝑌𝑉 )
14 13 biimpri ( 𝑌𝑉𝑌 ∈ 𝒫 𝑉 )
15 14 ad2antll ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → 𝑌 ∈ 𝒫 𝑉 )
16 fvexd ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → ( ‘ ( ( 𝑋 ) ∩ ( 𝑌 ) ) ) ∈ V )
17 fveq2 ( 𝑥 = 𝑋 → ( 𝑥 ) = ( 𝑋 ) )
18 17 ineq1d ( 𝑥 = 𝑋 → ( ( 𝑥 ) ∩ ( 𝑦 ) ) = ( ( 𝑋 ) ∩ ( 𝑦 ) ) )
19 18 fveq2d ( 𝑥 = 𝑋 → ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) = ( ‘ ( ( 𝑋 ) ∩ ( 𝑦 ) ) ) )
20 fveq2 ( 𝑦 = 𝑌 → ( 𝑦 ) = ( 𝑌 ) )
21 20 ineq2d ( 𝑦 = 𝑌 → ( ( 𝑋 ) ∩ ( 𝑦 ) ) = ( ( 𝑋 ) ∩ ( 𝑌 ) ) )
22 21 fveq2d ( 𝑦 = 𝑌 → ( ‘ ( ( 𝑋 ) ∩ ( 𝑦 ) ) ) = ( ‘ ( ( 𝑋 ) ∩ ( 𝑌 ) ) ) )
23 eqid ( 𝑥 ∈ 𝒫 𝑉 , 𝑦 ∈ 𝒫 𝑉 ↦ ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) ) = ( 𝑥 ∈ 𝒫 𝑉 , 𝑦 ∈ 𝒫 𝑉 ↦ ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) )
24 19 22 23 ovmpog ( ( 𝑋 ∈ 𝒫 𝑉𝑌 ∈ 𝒫 𝑉 ∧ ( ‘ ( ( 𝑋 ) ∩ ( 𝑌 ) ) ) ∈ V ) → ( 𝑋 ( 𝑥 ∈ 𝒫 𝑉 , 𝑦 ∈ 𝒫 𝑉 ↦ ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) ) 𝑌 ) = ( ‘ ( ( 𝑋 ) ∩ ( 𝑌 ) ) ) )
25 12 15 16 24 syl3anc ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → ( 𝑋 ( 𝑥 ∈ 𝒫 𝑉 , 𝑦 ∈ 𝒫 𝑉 ↦ ( ‘ ( ( 𝑥 ) ∩ ( 𝑦 ) ) ) ) 𝑌 ) = ( ‘ ( ( 𝑋 ) ∩ ( 𝑌 ) ) ) )
26 8 25 eqtrd ( ( ( 𝐾 ∈ HL ∧ 𝑊𝐻 ) ∧ ( 𝑋𝑉𝑌𝑉 ) ) → ( 𝑋 𝑌 ) = ( ‘ ( ( 𝑋 ) ∩ ( 𝑌 ) ) ) )