Metamath Proof Explorer


Theorem iunopab

Description: Move indexed union inside an ordered-pair class abstraction. (Contributed by Stefan O'Rear, 20-Feb-2015) Avoid ax-sep , ax-nul , ax-pr . (Revised by SN, 11-Nov-2024)

Ref Expression
Assertion iunopab 𝑧𝐴 { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ∃ 𝑧𝐴 𝜑 }

Proof

Step Hyp Ref Expression
1 elopabw ( 𝑤 ∈ V → ( 𝑤 ∈ { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } ↔ ∃ 𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ) )
2 1 elv ( 𝑤 ∈ { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } ↔ ∃ 𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) )
3 2 rexbii ( ∃ 𝑧𝐴 𝑤 ∈ { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } ↔ ∃ 𝑧𝐴𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) )
4 rexcom4 ( ∃ 𝑧𝐴𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ↔ ∃ 𝑥𝑧𝐴𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) )
5 rexcom4 ( ∃ 𝑧𝐴𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ↔ ∃ 𝑦𝑧𝐴 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) )
6 r19.42v ( ∃ 𝑧𝐴 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ↔ ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) )
7 6 exbii ( ∃ 𝑦𝑧𝐴 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ↔ ∃ 𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) )
8 5 7 bitri ( ∃ 𝑧𝐴𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ↔ ∃ 𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) )
9 8 exbii ( ∃ 𝑥𝑧𝐴𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ↔ ∃ 𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) )
10 4 9 bitri ( ∃ 𝑧𝐴𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ 𝜑 ) ↔ ∃ 𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) )
11 3 10 bitri ( ∃ 𝑧𝐴 𝑤 ∈ { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } ↔ ∃ 𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) )
12 11 abbii { 𝑤 ∣ ∃ 𝑧𝐴 𝑤 ∈ { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } } = { 𝑤 ∣ ∃ 𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) }
13 df-iun 𝑧𝐴 { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } = { 𝑤 ∣ ∃ 𝑧𝐴 𝑤 ∈ { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } }
14 df-opab { ⟨ 𝑥 , 𝑦 ⟩ ∣ ∃ 𝑧𝐴 𝜑 } = { 𝑤 ∣ ∃ 𝑥𝑦 ( 𝑤 = ⟨ 𝑥 , 𝑦 ⟩ ∧ ∃ 𝑧𝐴 𝜑 ) }
15 12 13 14 3eqtr4i 𝑧𝐴 { ⟨ 𝑥 , 𝑦 ⟩ ∣ 𝜑 } = { ⟨ 𝑥 , 𝑦 ⟩ ∣ ∃ 𝑧𝐴 𝜑 }