Metamath Proof Explorer


Theorem cgsex4gOLD

Description: Obsolete version of cgsex4g as of 28-Jun-2024. (Contributed by NM, 5-Aug-1995) Avoid ax-10 . (Revised by Gino Giotto, 20-Aug-2023) (Proof modification is discouraged.) (New usage is discouraged.)

Ref Expression
Hypotheses cgsex4gOLD.1 ( ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) → 𝜒 )
cgsex4gOLD.2 ( 𝜒 → ( 𝜑𝜓 ) )
Assertion cgsex4gOLD ( ( ( 𝐴𝑅𝐵𝑆 ) ∧ ( 𝐶𝑅𝐷𝑆 ) ) → ( ∃ 𝑥𝑦𝑧𝑤 ( 𝜒𝜑 ) ↔ 𝜓 ) )

Proof

Step Hyp Ref Expression
1 cgsex4gOLD.1 ( ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) → 𝜒 )
2 cgsex4gOLD.2 ( 𝜒 → ( 𝜑𝜓 ) )
3 2 biimpa ( ( 𝜒𝜑 ) → 𝜓 )
4 3 exlimivv ( ∃ 𝑧𝑤 ( 𝜒𝜑 ) → 𝜓 )
5 4 exlimivv ( ∃ 𝑥𝑦𝑧𝑤 ( 𝜒𝜑 ) → 𝜓 )
6 elisset ( 𝐴𝑅 → ∃ 𝑥 𝑥 = 𝐴 )
7 elisset ( 𝐵𝑆 → ∃ 𝑦 𝑦 = 𝐵 )
8 6 7 anim12i ( ( 𝐴𝑅𝐵𝑆 ) → ( ∃ 𝑥 𝑥 = 𝐴 ∧ ∃ 𝑦 𝑦 = 𝐵 ) )
9 exdistrv ( ∃ 𝑥𝑦 ( 𝑥 = 𝐴𝑦 = 𝐵 ) ↔ ( ∃ 𝑥 𝑥 = 𝐴 ∧ ∃ 𝑦 𝑦 = 𝐵 ) )
10 8 9 sylibr ( ( 𝐴𝑅𝐵𝑆 ) → ∃ 𝑥𝑦 ( 𝑥 = 𝐴𝑦 = 𝐵 ) )
11 elisset ( 𝐶𝑅 → ∃ 𝑧 𝑧 = 𝐶 )
12 elisset ( 𝐷𝑆 → ∃ 𝑤 𝑤 = 𝐷 )
13 11 12 anim12i ( ( 𝐶𝑅𝐷𝑆 ) → ( ∃ 𝑧 𝑧 = 𝐶 ∧ ∃ 𝑤 𝑤 = 𝐷 ) )
14 exdistrv ( ∃ 𝑧𝑤 ( 𝑧 = 𝐶𝑤 = 𝐷 ) ↔ ( ∃ 𝑧 𝑧 = 𝐶 ∧ ∃ 𝑤 𝑤 = 𝐷 ) )
15 13 14 sylibr ( ( 𝐶𝑅𝐷𝑆 ) → ∃ 𝑧𝑤 ( 𝑧 = 𝐶𝑤 = 𝐷 ) )
16 10 15 anim12i ( ( ( 𝐴𝑅𝐵𝑆 ) ∧ ( 𝐶𝑅𝐷𝑆 ) ) → ( ∃ 𝑥𝑦 ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ∃ 𝑧𝑤 ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) )
17 excom ( ∃ 𝑦𝑧𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) ↔ ∃ 𝑧𝑦𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) )
18 17 exbii ( ∃ 𝑥𝑦𝑧𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) ↔ ∃ 𝑥𝑧𝑦𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) )
19 4exdistrv ( ∃ 𝑥𝑧𝑦𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) ↔ ( ∃ 𝑥𝑦 ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ∃ 𝑧𝑤 ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) )
20 18 19 bitri ( ∃ 𝑥𝑦𝑧𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) ↔ ( ∃ 𝑥𝑦 ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ∃ 𝑧𝑤 ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) )
21 16 20 sylibr ( ( ( 𝐴𝑅𝐵𝑆 ) ∧ ( 𝐶𝑅𝐷𝑆 ) ) → ∃ 𝑥𝑦𝑧𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) )
22 1 2eximi ( ∃ 𝑧𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) → ∃ 𝑧𝑤 𝜒 )
23 22 2eximi ( ∃ 𝑥𝑦𝑧𝑤 ( ( 𝑥 = 𝐴𝑦 = 𝐵 ) ∧ ( 𝑧 = 𝐶𝑤 = 𝐷 ) ) → ∃ 𝑥𝑦𝑧𝑤 𝜒 )
24 21 23 syl ( ( ( 𝐴𝑅𝐵𝑆 ) ∧ ( 𝐶𝑅𝐷𝑆 ) ) → ∃ 𝑥𝑦𝑧𝑤 𝜒 )
25 2 biimprcd ( 𝜓 → ( 𝜒𝜑 ) )
26 25 ancld ( 𝜓 → ( 𝜒 → ( 𝜒𝜑 ) ) )
27 26 2eximdv ( 𝜓 → ( ∃ 𝑧𝑤 𝜒 → ∃ 𝑧𝑤 ( 𝜒𝜑 ) ) )
28 27 2eximdv ( 𝜓 → ( ∃ 𝑥𝑦𝑧𝑤 𝜒 → ∃ 𝑥𝑦𝑧𝑤 ( 𝜒𝜑 ) ) )
29 24 28 syl5com ( ( ( 𝐴𝑅𝐵𝑆 ) ∧ ( 𝐶𝑅𝐷𝑆 ) ) → ( 𝜓 → ∃ 𝑥𝑦𝑧𝑤 ( 𝜒𝜑 ) ) )
30 5 29 impbid2 ( ( ( 𝐴𝑅𝐵𝑆 ) ∧ ( 𝐶𝑅𝐷𝑆 ) ) → ( ∃ 𝑥𝑦𝑧𝑤 ( 𝜒𝜑 ) ↔ 𝜓 ) )