Metamath Proof Explorer


Theorem rru

Description: Relative version of Russell's paradox ru (which corresponds to the case A = _V ).

Originally a subproof in pwnss . (Contributed by Stefan O'Rear, 22-Feb-2015) Avoid df-nel . (Revised by Steven Nguyen, 23-Nov-2022) Reduce axiom usage. (Revised by Gino Giotto, 30-Aug-2024)

Ref Expression
Assertion rru ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴

Proof

Step Hyp Ref Expression
1 eleq12 ( ( 𝑥 = 𝑦𝑥 = 𝑦 ) → ( 𝑥𝑥𝑦𝑦 ) )
2 1 anidms ( 𝑥 = 𝑦 → ( 𝑥𝑥𝑦𝑦 ) )
3 2 notbid ( 𝑥 = 𝑦 → ( ¬ 𝑥𝑥 ↔ ¬ 𝑦𝑦 ) )
4 3 cbvrabv { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } = { 𝑦𝐴 ∣ ¬ 𝑦𝑦 }
5 4 eleq2i ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ↔ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑦𝐴 ∣ ¬ 𝑦𝑦 } )
6 elex ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑦𝐴 ∣ ¬ 𝑦𝑦 } → { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ V )
7 elex ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 → { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ V )
8 7 adantr ( ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 ∧ ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) → { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ V )
9 eleq1 ( 𝑦 = 𝑧 → ( 𝑦𝐴𝑧𝐴 ) )
10 id ( 𝑦 = 𝑧𝑦 = 𝑧 )
11 10 10 eleq12d ( 𝑦 = 𝑧 → ( 𝑦𝑦𝑧𝑧 ) )
12 11 notbid ( 𝑦 = 𝑧 → ( ¬ 𝑦𝑦 ↔ ¬ 𝑧𝑧 ) )
13 9 12 anbi12d ( 𝑦 = 𝑧 → ( ( 𝑦𝐴 ∧ ¬ 𝑦𝑦 ) ↔ ( 𝑧𝐴 ∧ ¬ 𝑧𝑧 ) ) )
14 eleq1 ( 𝑧 = { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } → ( 𝑧𝐴 ↔ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 ) )
15 eleq12 ( ( 𝑧 = { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∧ 𝑧 = { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) → ( 𝑧𝑧 ↔ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) )
16 15 anidms ( 𝑧 = { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } → ( 𝑧𝑧 ↔ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) )
17 16 notbid ( 𝑧 = { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } → ( ¬ 𝑧𝑧 ↔ ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) )
18 14 17 anbi12d ( 𝑧 = { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } → ( ( 𝑧𝐴 ∧ ¬ 𝑧𝑧 ) ↔ ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 ∧ ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) ) )
19 df-rab { 𝑦𝐴 ∣ ¬ 𝑦𝑦 } = { 𝑦 ∣ ( 𝑦𝐴 ∧ ¬ 𝑦𝑦 ) }
20 13 18 19 elab2gw ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ V → ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑦𝐴 ∣ ¬ 𝑦𝑦 } ↔ ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 ∧ ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) ) )
21 6 8 20 pm5.21nii ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑦𝐴 ∣ ¬ 𝑦𝑦 } ↔ ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 ∧ ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) )
22 5 21 bitri ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ↔ ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 ∧ ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) )
23 pclem6 ( ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ↔ ( { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 ∧ ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ) ) → ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴 )
24 22 23 ax-mp ¬ { 𝑥𝐴 ∣ ¬ 𝑥𝑥 } ∈ 𝐴