| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | cgsex4gOLD.2 | . . . . 5
⊢ (𝜒 → (𝜑 ↔ 𝜓)) | 
| 2 | 1 | biimpa 476 | . . . 4
⊢ ((𝜒 ∧ 𝜑) → 𝜓) | 
| 3 | 2 | exlimivv 1932 | . . 3
⊢
(∃𝑧∃𝑤(𝜒 ∧ 𝜑) → 𝜓) | 
| 4 | 3 | exlimivv 1932 | . 2
⊢
(∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑) → 𝜓) | 
| 5 |  | elisset 2823 | . . . . . . . 8
⊢ (𝐴 ∈ 𝑅 → ∃𝑥 𝑥 = 𝐴) | 
| 6 |  | elisset 2823 | . . . . . . . 8
⊢ (𝐵 ∈ 𝑆 → ∃𝑦 𝑦 = 𝐵) | 
| 7 | 5, 6 | anim12i 613 | . . . . . . 7
⊢ ((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) → (∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵)) | 
| 8 |  | exdistrv 1955 | . . . . . . 7
⊢
(∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ↔ (∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵)) | 
| 9 | 7, 8 | sylibr 234 | . . . . . 6
⊢ ((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) → ∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵)) | 
| 10 |  | elisset 2823 | . . . . . . . 8
⊢ (𝐶 ∈ 𝑅 → ∃𝑧 𝑧 = 𝐶) | 
| 11 |  | elisset 2823 | . . . . . . . 8
⊢ (𝐷 ∈ 𝑆 → ∃𝑤 𝑤 = 𝐷) | 
| 12 | 10, 11 | anim12i 613 | . . . . . . 7
⊢ ((𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆) → (∃𝑧 𝑧 = 𝐶 ∧ ∃𝑤 𝑤 = 𝐷)) | 
| 13 |  | exdistrv 1955 | . . . . . . 7
⊢
(∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷) ↔ (∃𝑧 𝑧 = 𝐶 ∧ ∃𝑤 𝑤 = 𝐷)) | 
| 14 | 12, 13 | sylibr 234 | . . . . . 6
⊢ ((𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆) → ∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) | 
| 15 | 9, 14 | anim12i 613 | . . . . 5
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → (∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ ∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 16 |  | eqeq1 2741 | . . . . . . . . . . . . . 14
⊢ (𝑦 = 𝑣 → (𝑦 = 𝐵 ↔ 𝑣 = 𝐵)) | 
| 17 | 16 | anbi2d 630 | . . . . . . . . . . . . 13
⊢ (𝑦 = 𝑣 → ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ↔ (𝑥 = 𝐴 ∧ 𝑣 = 𝐵))) | 
| 18 | 17 | anbi1d 631 | . . . . . . . . . . . 12
⊢ (𝑦 = 𝑣 → (((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ((𝑥 = 𝐴 ∧ 𝑣 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)))) | 
| 19 | 18 | exbidv 1921 | . . . . . . . . . . 11
⊢ (𝑦 = 𝑣 → (∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ∃𝑤((𝑥 = 𝐴 ∧ 𝑣 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)))) | 
| 20 | 19 | notbid 318 | . . . . . . . . . 10
⊢ (𝑦 = 𝑣 → (¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑣 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)))) | 
| 21 |  | eqeq1 2741 | . . . . . . . . . . . . . 14
⊢ (𝑧 = 𝑣 → (𝑧 = 𝐶 ↔ 𝑣 = 𝐶)) | 
| 22 | 21 | anbi1d 631 | . . . . . . . . . . . . 13
⊢ (𝑧 = 𝑣 → ((𝑧 = 𝐶 ∧ 𝑤 = 𝐷) ↔ (𝑣 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 23 | 22 | anbi2d 630 | . . . . . . . . . . . 12
⊢ (𝑧 = 𝑣 → (((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑣 = 𝐶 ∧ 𝑤 = 𝐷)))) | 
| 24 | 23 | exbidv 1921 | . . . . . . . . . . 11
⊢ (𝑧 = 𝑣 → (∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑣 = 𝐶 ∧ 𝑤 = 𝐷)))) | 
| 25 | 24 | notbid 318 | . . . . . . . . . 10
⊢ (𝑧 = 𝑣 → (¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑣 = 𝐶 ∧ 𝑤 = 𝐷)))) | 
| 26 | 20, 25 | alcomw 2044 | . . . . . . . . 9
⊢
(∀𝑦∀𝑧 ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ∀𝑧∀𝑦 ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 27 | 26 | notbii 320 | . . . . . . . 8
⊢ (¬
∀𝑦∀𝑧 ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ¬ ∀𝑧∀𝑦 ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 28 |  | 2exnaln 1829 | . . . . . . . 8
⊢
(∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ¬ ∀𝑦∀𝑧 ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 29 |  | 2exnaln 1829 | . . . . . . . 8
⊢
(∃𝑧∃𝑦∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ¬ ∀𝑧∀𝑦 ¬ ∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 30 | 27, 28, 29 | 3bitr4i 303 | . . . . . . 7
⊢
(∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ∃𝑧∃𝑦∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 31 | 30 | exbii 1848 | . . . . . 6
⊢
(∃𝑥∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ ∃𝑥∃𝑧∃𝑦∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 32 |  | 4exdistrv 1956 | . . . . . 6
⊢
(∃𝑥∃𝑧∃𝑦∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ (∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ ∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 33 | 31, 32 | bitri 275 | . . . . 5
⊢
(∃𝑥∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) ↔ (∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ ∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 34 | 15, 33 | sylibr 234 | . . . 4
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → ∃𝑥∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 35 |  | cgsex4gOLD.1 | . . . . . 6
⊢ (((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) → 𝜒) | 
| 36 | 35 | 2eximi 1836 | . . . . 5
⊢
(∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) → ∃𝑧∃𝑤𝜒) | 
| 37 | 36 | 2eximi 1836 | . . . 4
⊢
(∃𝑥∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) → ∃𝑥∃𝑦∃𝑧∃𝑤𝜒) | 
| 38 | 34, 37 | syl 17 | . . 3
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → ∃𝑥∃𝑦∃𝑧∃𝑤𝜒) | 
| 39 | 1 | biimprcd 250 | . . . . . 6
⊢ (𝜓 → (𝜒 → 𝜑)) | 
| 40 | 39 | ancld 550 | . . . . 5
⊢ (𝜓 → (𝜒 → (𝜒 ∧ 𝜑))) | 
| 41 | 40 | 2eximdv 1919 | . . . 4
⊢ (𝜓 → (∃𝑧∃𝑤𝜒 → ∃𝑧∃𝑤(𝜒 ∧ 𝜑))) | 
| 42 | 41 | 2eximdv 1919 | . . 3
⊢ (𝜓 → (∃𝑥∃𝑦∃𝑧∃𝑤𝜒 → ∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑))) | 
| 43 | 38, 42 | syl5com 31 | . 2
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → (𝜓 → ∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑))) | 
| 44 | 4, 43 | impbid2 226 | 1
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → (∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑) ↔ 𝜓)) |