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Theorem abexssex 7965
Description: Existence of a class abstraction with an existentially quantified expression. Both 𝑥 and 𝑦 can be free in 𝜑. (Contributed by NM, 29-Jul-2006.)
Hypotheses
Ref Expression
abrexex2.1 𝐴 ∈ V
abrexex2.2 {𝑦𝜑} ∈ V
Assertion
Ref Expression
abexssex {𝑦 ∣ ∃𝑥(𝑥𝐴𝜑)} ∈ V
Distinct variable group:   𝑥,𝑦,𝐴
Allowed substitution hints:   𝜑(𝑥, 𝑦)

Proof of Theorem abexssex
StepHypRef Expression
1 df-rex 3089 . . . 4 (∃𝑥 ∈ 𝒫 𝐴𝜑 ↔ ∃𝑥(𝑥 ∈ 𝒫 𝐴𝜑))
2 velpw 4566 . . . . . 6 (𝑥 ∈ 𝒫 𝐴𝑥𝐴)
32anbi1i 635 . . . . 5 ((𝑥 ∈ 𝒫 𝐴𝜑) ↔ (𝑥𝐴𝜑))
43exbii 1877 . . . 4 (∃𝑥(𝑥 ∈ 𝒫 𝐴𝜑) ↔ ∃𝑥(𝑥𝐴𝜑))
51, 4bitri 278 . . 3 (∃𝑥 ∈ 𝒫 𝐴𝜑 ↔ ∃𝑥(𝑥𝐴𝜑))
65abbii 2829 . 2 {𝑦 ∣ ∃𝑥 ∈ 𝒫 𝐴𝜑} = {𝑦 ∣ ∃𝑥(𝑥𝐴𝜑)}
7 abrexex2.1 . . . 4 𝐴 ∈ V
87pwex 5350 . . 3 𝒫 𝐴 ∈ V
9 abrexex2.2 . . 3 {𝑦𝜑} ∈ V
108, 9abrexex2 7964 . 2 {𝑦 ∣ ∃𝑥 ∈ 𝒫 𝐴𝜑} ∈ V
116, 10eqeltrri 2859 1 {𝑦 ∣ ∃𝑥(𝑥𝐴𝜑)} ∈ V
Colors of variables:    wff setvar class
This proof depends on syntax axioms:  wa 400  wex 1808  wcel 2142  {cab 2740  wrex 3088  Vcvv 3454  wss 3904  𝒫 cpw 4561
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1824  ax-4 1838  ax-5 1939  ax-6 1996  ax-7 2037  ax-8 2144  ax-9 2152  ax-10 2175  ax-11 2191  ax-12 2212  ax-ext 2734  ax-rep 5237  ax-sep 5256  ax-pow 5335  ax-un 7734
This proof depends on definitions:  df-bi 210  df-an 401  df-or 861  df-tru 1572  df-ex 1809  df-nf 1813  df-sb 2096  df-mo 2566  df-clab 2741  df-cleq 2754  df-clel 2837  df-nfc 2911  df-ral 3079  df-rex 3089  df-v 3456  df-ss 3921  df-pw 4563  df-uni 4872  df-iun 4957
This theorem is used by: (None)
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