Metamath Proof Explorer


Theorem elptr

Description: A basic open set in the product topology. (Contributed by Mario Carneiro, 3-Feb-2015)

Ref Expression
Hypothesis ptbas.1 𝐵 = { 𝑥 ∣ ∃ 𝑔 ( ( 𝑔 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑔𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑧 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑧 ) ( 𝑔𝑦 ) = ( 𝐹𝑦 ) ) ∧ 𝑥 = X 𝑦𝐴 ( 𝑔𝑦 ) ) }
Assertion elptr ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → X 𝑦𝐴 ( 𝐺𝑦 ) ∈ 𝐵 )

Proof

Step Hyp Ref Expression
1 ptbas.1 𝐵 = { 𝑥 ∣ ∃ 𝑔 ( ( 𝑔 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑔𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑧 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑧 ) ( 𝑔𝑦 ) = ( 𝐹𝑦 ) ) ∧ 𝑥 = X 𝑦𝐴 ( 𝑔𝑦 ) ) }
2 simp2l ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → 𝐺 Fn 𝐴 )
3 simp1 ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → 𝐴𝑉 )
4 2 3 fnexd ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → 𝐺 ∈ V )
5 simp2r ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) )
6 difeq2 ( 𝑤 = 𝑊 → ( 𝐴𝑤 ) = ( 𝐴𝑊 ) )
7 6 raleqdv ( 𝑤 = 𝑊 → ( ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ↔ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) )
8 7 rspcev ( ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) → ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) )
9 8 3ad2ant3 ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) )
10 2 5 9 3jca ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) )
11 fveq1 ( = 𝐺 → ( 𝑦 ) = ( 𝐺𝑦 ) )
12 11 eqcomd ( = 𝐺 → ( 𝐺𝑦 ) = ( 𝑦 ) )
13 12 ixpeq2dv ( = 𝐺X 𝑦𝐴 ( 𝐺𝑦 ) = X 𝑦𝐴 ( 𝑦 ) )
14 13 biantrud ( = 𝐺 → ( ( Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝑦 ) = ( 𝐹𝑦 ) ) ↔ ( ( Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝑦 ) = ( 𝐹𝑦 ) ) ∧ X 𝑦𝐴 ( 𝐺𝑦 ) = X 𝑦𝐴 ( 𝑦 ) ) ) )
15 fneq1 ( = 𝐺 → ( Fn 𝐴𝐺 Fn 𝐴 ) )
16 11 eleq1d ( = 𝐺 → ( ( 𝑦 ) ∈ ( 𝐹𝑦 ) ↔ ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) )
17 16 ralbidv ( = 𝐺 → ( ∀ 𝑦𝐴 ( 𝑦 ) ∈ ( 𝐹𝑦 ) ↔ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) )
18 11 eqeq1d ( = 𝐺 → ( ( 𝑦 ) = ( 𝐹𝑦 ) ↔ ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) )
19 18 rexralbidv ( = 𝐺 → ( ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝑦 ) = ( 𝐹𝑦 ) ↔ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) )
20 15 17 19 3anbi123d ( = 𝐺 → ( ( Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝑦 ) = ( 𝐹𝑦 ) ) ↔ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) )
21 14 20 bitr3d ( = 𝐺 → ( ( ( Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝑦 ) = ( 𝐹𝑦 ) ) ∧ X 𝑦𝐴 ( 𝐺𝑦 ) = X 𝑦𝐴 ( 𝑦 ) ) ↔ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) )
22 4 10 21 spcedv ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → ∃ ( ( Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝑦 ) = ( 𝐹𝑦 ) ) ∧ X 𝑦𝐴 ( 𝐺𝑦 ) = X 𝑦𝐴 ( 𝑦 ) ) )
23 1 elpt ( X 𝑦𝐴 ( 𝐺𝑦 ) ∈ 𝐵 ↔ ∃ ( ( Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝑦 ) ∈ ( 𝐹𝑦 ) ∧ ∃ 𝑤 ∈ Fin ∀ 𝑦 ∈ ( 𝐴𝑤 ) ( 𝑦 ) = ( 𝐹𝑦 ) ) ∧ X 𝑦𝐴 ( 𝐺𝑦 ) = X 𝑦𝐴 ( 𝑦 ) ) )
24 22 23 sylibr ( ( 𝐴𝑉 ∧ ( 𝐺 Fn 𝐴 ∧ ∀ 𝑦𝐴 ( 𝐺𝑦 ) ∈ ( 𝐹𝑦 ) ) ∧ ( 𝑊 ∈ Fin ∧ ∀ 𝑦 ∈ ( 𝐴𝑊 ) ( 𝐺𝑦 ) = ( 𝐹𝑦 ) ) ) → X 𝑦𝐴 ( 𝐺𝑦 ) ∈ 𝐵 )