Metamath Proof Explorer


Theorem disjenex

Description: Existence version of disjen . (Contributed by Mario Carneiro, 7-Feb-2015)

Ref Expression
Assertion disjenex ( ( 𝐴𝑉𝐵𝑊 ) → ∃ 𝑥 ( ( 𝐴𝑥 ) = ∅ ∧ 𝑥𝐵 ) )

Proof

Step Hyp Ref Expression
1 simpr ( ( 𝐴𝑉𝐵𝑊 ) → 𝐵𝑊 )
2 snex { 𝒫 ran 𝐴 } ∈ V
3 xpexg ( ( 𝐵𝑊 ∧ { 𝒫 ran 𝐴 } ∈ V ) → ( 𝐵 × { 𝒫 ran 𝐴 } ) ∈ V )
4 1 2 3 sylancl ( ( 𝐴𝑉𝐵𝑊 ) → ( 𝐵 × { 𝒫 ran 𝐴 } ) ∈ V )
5 disjen ( ( 𝐴𝑉𝐵𝑊 ) → ( ( 𝐴 ∩ ( 𝐵 × { 𝒫 ran 𝐴 } ) ) = ∅ ∧ ( 𝐵 × { 𝒫 ran 𝐴 } ) ≈ 𝐵 ) )
6 ineq2 ( 𝑥 = ( 𝐵 × { 𝒫 ran 𝐴 } ) → ( 𝐴𝑥 ) = ( 𝐴 ∩ ( 𝐵 × { 𝒫 ran 𝐴 } ) ) )
7 6 eqeq1d ( 𝑥 = ( 𝐵 × { 𝒫 ran 𝐴 } ) → ( ( 𝐴𝑥 ) = ∅ ↔ ( 𝐴 ∩ ( 𝐵 × { 𝒫 ran 𝐴 } ) ) = ∅ ) )
8 breq1 ( 𝑥 = ( 𝐵 × { 𝒫 ran 𝐴 } ) → ( 𝑥𝐵 ↔ ( 𝐵 × { 𝒫 ran 𝐴 } ) ≈ 𝐵 ) )
9 7 8 anbi12d ( 𝑥 = ( 𝐵 × { 𝒫 ran 𝐴 } ) → ( ( ( 𝐴𝑥 ) = ∅ ∧ 𝑥𝐵 ) ↔ ( ( 𝐴 ∩ ( 𝐵 × { 𝒫 ran 𝐴 } ) ) = ∅ ∧ ( 𝐵 × { 𝒫 ran 𝐴 } ) ≈ 𝐵 ) ) )
10 4 5 9 spcedv ( ( 𝐴𝑉𝐵𝑊 ) → ∃ 𝑥 ( ( 𝐴𝑥 ) = ∅ ∧ 𝑥𝐵 ) )