Metamath Proof Explorer


Theorem resvsca

Description: Base set of a structure restriction. (Contributed by Thierry Arnoux, 6-Sep-2018)

Ref Expression
Hypotheses resvsca.r 𝑅 = ( 𝑊v 𝐴 )
resvsca.f 𝐹 = ( Scalar ‘ 𝑊 )
resvsca.b 𝐵 = ( Base ‘ 𝐹 )
Assertion resvsca ( 𝐴𝑉 → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) )

Proof

Step Hyp Ref Expression
1 resvsca.r 𝑅 = ( 𝑊v 𝐴 )
2 resvsca.f 𝐹 = ( Scalar ‘ 𝑊 )
3 resvsca.b 𝐵 = ( Base ‘ 𝐹 )
4 2 fvexi 𝐹 ∈ V
5 eqid ( 𝐹s 𝐴 ) = ( 𝐹s 𝐴 )
6 5 3 ressid2 ( ( 𝐵𝐴𝐹 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = 𝐹 )
7 4 6 mp3an2 ( ( 𝐵𝐴𝐴𝑉 ) → ( 𝐹s 𝐴 ) = 𝐹 )
8 7 3adant2 ( ( 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = 𝐹 )
9 1 2 3 resvid2 ( ( 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → 𝑅 = 𝑊 )
10 9 fveq2d ( ( 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → ( Scalar ‘ 𝑅 ) = ( Scalar ‘ 𝑊 ) )
11 2 8 10 3eqtr4a ( ( 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) )
12 11 3expib ( 𝐵𝐴 → ( ( 𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) ) )
13 simp2 ( ( ¬ 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → 𝑊 ∈ V )
14 ovex ( 𝐹s 𝐴 ) ∈ V
15 scaid Scalar = Slot ( Scalar ‘ ndx )
16 15 setsid ( ( 𝑊 ∈ V ∧ ( 𝐹s 𝐴 ) ∈ V ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ ( 𝑊 sSet ⟨ ( Scalar ‘ ndx ) , ( 𝐹s 𝐴 ) ⟩ ) ) )
17 13 14 16 sylancl ( ( ¬ 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ ( 𝑊 sSet ⟨ ( Scalar ‘ ndx ) , ( 𝐹s 𝐴 ) ⟩ ) ) )
18 1 2 3 resvval2 ( ( ¬ 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → 𝑅 = ( 𝑊 sSet ⟨ ( Scalar ‘ ndx ) , ( 𝐹s 𝐴 ) ⟩ ) )
19 18 fveq2d ( ( ¬ 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → ( Scalar ‘ 𝑅 ) = ( Scalar ‘ ( 𝑊 sSet ⟨ ( Scalar ‘ ndx ) , ( 𝐹s 𝐴 ) ⟩ ) ) )
20 17 19 eqtr4d ( ( ¬ 𝐵𝐴𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) )
21 20 3expib ( ¬ 𝐵𝐴 → ( ( 𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) ) )
22 12 21 pm2.61i ( ( 𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) )
23 0fv ( ∅ ‘ ( Scalar ‘ ndx ) ) = ∅
24 0ex ∅ ∈ V
25 24 15 strfvn ( Scalar ‘ ∅ ) = ( ∅ ‘ ( Scalar ‘ ndx ) )
26 ress0 ( ∅ ↾s 𝐴 ) = ∅
27 23 25 26 3eqtr4ri ( ∅ ↾s 𝐴 ) = ( Scalar ‘ ∅ )
28 fvprc ( ¬ 𝑊 ∈ V → ( Scalar ‘ 𝑊 ) = ∅ )
29 2 28 syl5eq ( ¬ 𝑊 ∈ V → 𝐹 = ∅ )
30 29 oveq1d ( ¬ 𝑊 ∈ V → ( 𝐹s 𝐴 ) = ( ∅ ↾s 𝐴 ) )
31 reldmresv Rel dom ↾v
32 31 ovprc1 ( ¬ 𝑊 ∈ V → ( 𝑊v 𝐴 ) = ∅ )
33 1 32 syl5eq ( ¬ 𝑊 ∈ V → 𝑅 = ∅ )
34 33 fveq2d ( ¬ 𝑊 ∈ V → ( Scalar ‘ 𝑅 ) = ( Scalar ‘ ∅ ) )
35 27 30 34 3eqtr4a ( ¬ 𝑊 ∈ V → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) )
36 35 adantr ( ( ¬ 𝑊 ∈ V ∧ 𝐴𝑉 ) → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) )
37 22 36 pm2.61ian ( 𝐴𝑉 → ( 𝐹s 𝐴 ) = ( Scalar ‘ 𝑅 ) )