Theorem pwpwab 5070

Description: The double power class written as a class abstraction: the class of sets whose union is included in the given class. (Contributed by BJ, 29-Apr-2021.)

Assertion

Ref	Expression
pwpwab	⊢ 𝒫 𝒫 𝐴 = {𝑥 ∣ ∪ 𝑥 ⊆ 𝐴}

Distinct variable group:   𝑥,𝐴

Proof of Theorem pwpwab

Step	Hyp	Ref	Expression
1		vex 3454	. . 3 ⊢ 𝑥 ∈ V
2		elpwpw 5069	. . 3 ⊢ (𝑥 ∈ 𝒫 𝒫 𝐴 ↔ (𝑥 ∈ V ∧ ∪ 𝑥 ⊆ 𝐴))
3	1, 2	mpbiran 709	. 2 ⊢ (𝑥 ∈ 𝒫 𝒫 𝐴 ↔ ∪ 𝑥 ⊆ 𝐴)
4	3	eqabi 2864	1 ⊢ 𝒫 𝒫 𝐴 = {𝑥 ∣ ∪ 𝑥 ⊆ 𝐴}

Syntax hints:   = wceq 1540   ∈ wcel 2109  {cab 2708  Vcvv 3450   ⊆ wss 3917  𝒫 cpw 4566  ∪ cuni 4874

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1795  ax-4 1809  ax-5 1910  ax-6 1967  ax-7 2008  ax-8 2111  ax-9 2119  ax-ext 2702

This theorem depends on definitions:  df-bi 207  df-an 396  df-tru 1543  df-ex 1780  df-sb 2066  df-clab 2709  df-cleq 2722  df-clel 2804  df-ral 3046  df-v 3452  df-ss 3934  df-pw 4568  df-uni 4875

This theorem is referenced by:  pwpwssunieq  5071