Metamath Proof Explorer


Theorem kmlem3

Description: Lemma for 5-quantifier AC of Kurt Maes, Th. 4, part of 3 => 4. The right-hand side is part of the hypothesis of 4. (Contributed by NM, 25-Mar-2004)

Ref Expression
Assertion kmlem3 ( ( 𝑧 ( 𝑥 ∖ { 𝑧 } ) ) ≠ ∅ ↔ ∃ 𝑣𝑧𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )

Proof

Step Hyp Ref Expression
1 dfdif2 ( 𝑧 ( 𝑥 ∖ { 𝑧 } ) ) = { 𝑣𝑧 ∣ ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) }
2 dfnul3 ∅ = { 𝑣𝑧 ∣ ¬ 𝑣𝑧 }
3 2 uneq2i ( { 𝑣𝑧 ∣ ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) } ∪ ∅ ) = ( { 𝑣𝑧 ∣ ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) } ∪ { 𝑣𝑧 ∣ ¬ 𝑣𝑧 } )
4 un0 ( { 𝑣𝑧 ∣ ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) } ∪ ∅ ) = { 𝑣𝑧 ∣ ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) }
5 unrab ( { 𝑣𝑧 ∣ ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) } ∪ { 𝑣𝑧 ∣ ¬ 𝑣𝑧 } ) = { 𝑣𝑧 ∣ ( ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∨ ¬ 𝑣𝑧 ) }
6 3 4 5 3eqtr3i { 𝑣𝑧 ∣ ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) } = { 𝑣𝑧 ∣ ( ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∨ ¬ 𝑣𝑧 ) }
7 ianor ( ¬ ( 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∧ 𝑣𝑧 ) ↔ ( ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∨ ¬ 𝑣𝑧 ) )
8 eluni ( 𝑣 ( 𝑥 ∖ { 𝑧 } ) ↔ ∃ 𝑤 ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) )
9 8 anbi1i ( ( 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∧ 𝑣𝑧 ) ↔ ( ∃ 𝑤 ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) )
10 df-rex ( ∃ 𝑤𝑥 ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ↔ ∃ 𝑤 ( 𝑤𝑥 ∧ ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ) )
11 elin ( 𝑣 ∈ ( 𝑧𝑤 ) ↔ ( 𝑣𝑧𝑣𝑤 ) )
12 11 anbi2i ( ( 𝑧𝑤𝑣 ∈ ( 𝑧𝑤 ) ) ↔ ( 𝑧𝑤 ∧ ( 𝑣𝑧𝑣𝑤 ) ) )
13 df-an ( ( 𝑧𝑤𝑣 ∈ ( 𝑧𝑤 ) ) ↔ ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )
14 12 13 bitr3i ( ( 𝑧𝑤 ∧ ( 𝑣𝑧𝑣𝑤 ) ) ↔ ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )
15 14 anbi2i ( ( 𝑤𝑥 ∧ ( 𝑧𝑤 ∧ ( 𝑣𝑧𝑣𝑤 ) ) ) ↔ ( 𝑤𝑥 ∧ ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ) )
16 eldifsn ( 𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ↔ ( 𝑤𝑥𝑤𝑧 ) )
17 necom ( 𝑤𝑧𝑧𝑤 )
18 17 anbi2i ( ( 𝑤𝑥𝑤𝑧 ) ↔ ( 𝑤𝑥𝑧𝑤 ) )
19 16 18 bitri ( 𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ↔ ( 𝑤𝑥𝑧𝑤 ) )
20 19 anbi2i ( ( ( 𝑣𝑤𝑣𝑧 ) ∧ 𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ↔ ( ( 𝑣𝑤𝑣𝑧 ) ∧ ( 𝑤𝑥𝑧𝑤 ) ) )
21 ancom ( ( 𝑣𝑤𝑣𝑧 ) ↔ ( 𝑣𝑧𝑣𝑤 ) )
22 21 anbi2ci ( ( ( 𝑣𝑤𝑣𝑧 ) ∧ ( 𝑤𝑥𝑧𝑤 ) ) ↔ ( ( 𝑤𝑥𝑧𝑤 ) ∧ ( 𝑣𝑧𝑣𝑤 ) ) )
23 anass ( ( ( 𝑤𝑥𝑧𝑤 ) ∧ ( 𝑣𝑧𝑣𝑤 ) ) ↔ ( 𝑤𝑥 ∧ ( 𝑧𝑤 ∧ ( 𝑣𝑧𝑣𝑤 ) ) ) )
24 20 22 23 3bitri ( ( ( 𝑣𝑤𝑣𝑧 ) ∧ 𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ↔ ( 𝑤𝑥 ∧ ( 𝑧𝑤 ∧ ( 𝑣𝑧𝑣𝑤 ) ) ) )
25 an32 ( ( ( 𝑣𝑤𝑣𝑧 ) ∧ 𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ↔ ( ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) )
26 24 25 bitr3i ( ( 𝑤𝑥 ∧ ( 𝑧𝑤 ∧ ( 𝑣𝑧𝑣𝑤 ) ) ) ↔ ( ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) )
27 15 26 bitr3i ( ( 𝑤𝑥 ∧ ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ) ↔ ( ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) )
28 27 exbii ( ∃ 𝑤 ( 𝑤𝑥 ∧ ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ) ↔ ∃ 𝑤 ( ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) )
29 19.41v ( ∃ 𝑤 ( ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) ↔ ( ∃ 𝑤 ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) )
30 10 28 29 3bitri ( ∃ 𝑤𝑥 ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ↔ ( ∃ 𝑤 ( 𝑣𝑤𝑤 ∈ ( 𝑥 ∖ { 𝑧 } ) ) ∧ 𝑣𝑧 ) )
31 rexnal ( ∃ 𝑤𝑥 ¬ ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ↔ ¬ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )
32 9 30 31 3bitr2ri ( ¬ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) ↔ ( 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∧ 𝑣𝑧 ) )
33 32 con1bii ( ¬ ( 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∧ 𝑣𝑧 ) ↔ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )
34 7 33 bitr3i ( ( ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∨ ¬ 𝑣𝑧 ) ↔ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )
35 34 rabbii { 𝑣𝑧 ∣ ( ¬ 𝑣 ( 𝑥 ∖ { 𝑧 } ) ∨ ¬ 𝑣𝑧 ) } = { 𝑣𝑧 ∣ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) }
36 1 6 35 3eqtri ( 𝑧 ( 𝑥 ∖ { 𝑧 } ) ) = { 𝑣𝑧 ∣ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) }
37 36 neeq1i ( ( 𝑧 ( 𝑥 ∖ { 𝑧 } ) ) ≠ ∅ ↔ { 𝑣𝑧 ∣ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) } ≠ ∅ )
38 rabn0 ( { 𝑣𝑧 ∣ ∀ 𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) } ≠ ∅ ↔ ∃ 𝑣𝑧𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )
39 37 38 bitri ( ( 𝑧 ( 𝑥 ∖ { 𝑧 } ) ) ≠ ∅ ↔ ∃ 𝑣𝑧𝑤𝑥 ( 𝑧𝑤 → ¬ 𝑣 ∈ ( 𝑧𝑤 ) ) )