Theorem bj-ismoored0 33061

Description: Necessary condition to be a Moore collection. (Contributed by BJ, 9-Dec-2021.)

Assertion

Ref	Expression
bj-ismoored0	⊢ (𝐴 ∈ Moore → ∪ 𝐴 ∈ 𝐴)

Proof of Theorem bj-ismoored0

Dummy variable 𝑥 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		bj-ismoore 33059	. . 3 ⊢ (𝐴 ∈ Moore → (𝐴 ∈ Moore ↔ ∀𝑥 ∈ 𝒫 𝐴(∪ 𝐴 ∩ ∩ 𝑥) ∈ 𝐴))
2		0elpw 4834	. . . 4 ⊢ ∅ ∈ 𝒫 𝐴
3		rint0 4517	. . . . . 6 ⊢ (𝑥 = ∅ → (∪ 𝐴 ∩ ∩ 𝑥) = ∪ 𝐴)
4	3	eleq1d 2686	. . . . 5 ⊢ (𝑥 = ∅ → ((∪ 𝐴 ∩ ∩ 𝑥) ∈ 𝐴 ↔ ∪ 𝐴 ∈ 𝐴))
5	4	rspcv 3305	. . . 4 ⊢ (∅ ∈ 𝒫 𝐴 → (∀𝑥 ∈ 𝒫 𝐴(∪ 𝐴 ∩ ∩ 𝑥) ∈ 𝐴 → ∪ 𝐴 ∈ 𝐴))
6	2, 5	ax-mp 5	. . 3 ⊢ (∀𝑥 ∈ 𝒫 𝐴(∪ 𝐴 ∩ ∩ 𝑥) ∈ 𝐴 → ∪ 𝐴 ∈ 𝐴)
7	1, 6	syl6bi 243	. 2 ⊢ (𝐴 ∈ Moore → (𝐴 ∈ Moore → ∪ 𝐴 ∈ 𝐴))
8	7	pm2.43i 52	1 ⊢ (𝐴 ∈ Moore → ∪ 𝐴 ∈ 𝐴)

Syntax hints:   → wi 4   = wceq 1483   ∈ wcel 1990  ∀wral 2912   ∩ cin 3573  ∅c0 3915  𝒫 cpw 4158  ∪ cuni 4436  ∩ cint 4475  Moorecmoore 33057

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602  ax-nul 4789

This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ral 2917  df-rex 2918  df-v 3202  df-dif 3577  df-in 3581  df-ss 3588  df-nul 3916  df-pw 4160  df-uni 4437  df-int 4476  df-bj-moore 33058

This theorem is referenced by:  bj-0nmoore  33067