Proof of Theorem cgsex4g
| Step | Hyp | Ref
 | Expression | 
| 1 |   | cgsex4g.2 | 
. . . . 5
⊢ (𝜒 → (𝜑 ↔ 𝜓)) | 
| 2 | 1 | biimpa 296 | 
. . . 4
⊢ ((𝜒 ∧ 𝜑) → 𝜓) | 
| 3 | 2 | exlimivv 1911 | 
. . 3
⊢
(∃𝑧∃𝑤(𝜒 ∧ 𝜑) → 𝜓) | 
| 4 | 3 | exlimivv 1911 | 
. 2
⊢
(∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑) → 𝜓) | 
| 5 |   | elisset 2777 | 
. . . . . . . 8
⊢ (𝐴 ∈ 𝑅 → ∃𝑥 𝑥 = 𝐴) | 
| 6 |   | elisset 2777 | 
. . . . . . . 8
⊢ (𝐵 ∈ 𝑆 → ∃𝑦 𝑦 = 𝐵) | 
| 7 | 5, 6 | anim12i 338 | 
. . . . . . 7
⊢ ((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) → (∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵)) | 
| 8 |   | eeanv 1951 | 
. . . . . . 7
⊢
(∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ↔ (∃𝑥 𝑥 = 𝐴 ∧ ∃𝑦 𝑦 = 𝐵)) | 
| 9 | 7, 8 | sylibr 134 | 
. . . . . 6
⊢ ((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) → ∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵)) | 
| 10 |   | elisset 2777 | 
. . . . . . . 8
⊢ (𝐶 ∈ 𝑅 → ∃𝑧 𝑧 = 𝐶) | 
| 11 |   | elisset 2777 | 
. . . . . . . 8
⊢ (𝐷 ∈ 𝑆 → ∃𝑤 𝑤 = 𝐷) | 
| 12 | 10, 11 | anim12i 338 | 
. . . . . . 7
⊢ ((𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆) → (∃𝑧 𝑧 = 𝐶 ∧ ∃𝑤 𝑤 = 𝐷)) | 
| 13 |   | eeanv 1951 | 
. . . . . . 7
⊢
(∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷) ↔ (∃𝑧 𝑧 = 𝐶 ∧ ∃𝑤 𝑤 = 𝐷)) | 
| 14 | 12, 13 | sylibr 134 | 
. . . . . 6
⊢ ((𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆) → ∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) | 
| 15 | 9, 14 | anim12i 338 | 
. . . . 5
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → (∃𝑥∃𝑦(𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ ∃𝑧∃𝑤(𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 16 |   | ee4anv 1953 | 
. . . . 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))) | 
| 17 | 15, 16 | sylibr 134 | 
. . . 4
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → ∃𝑥∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷))) | 
| 18 |   | cgsex4g.1 | 
. . . . . 6
⊢ (((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) → 𝜒) | 
| 19 | 18 | 2eximi 1615 | 
. . . . 5
⊢
(∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) → ∃𝑧∃𝑤𝜒) | 
| 20 | 19 | 2eximi 1615 | 
. . . 4
⊢
(∃𝑥∃𝑦∃𝑧∃𝑤((𝑥 = 𝐴 ∧ 𝑦 = 𝐵) ∧ (𝑧 = 𝐶 ∧ 𝑤 = 𝐷)) → ∃𝑥∃𝑦∃𝑧∃𝑤𝜒) | 
| 21 | 17, 20 | syl 14 | 
. . 3
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → ∃𝑥∃𝑦∃𝑧∃𝑤𝜒) | 
| 22 | 1 | biimprcd 160 | 
. . . . . 6
⊢ (𝜓 → (𝜒 → 𝜑)) | 
| 23 | 22 | ancld 325 | 
. . . . 5
⊢ (𝜓 → (𝜒 → (𝜒 ∧ 𝜑))) | 
| 24 | 23 | 2eximdv 1896 | 
. . . 4
⊢ (𝜓 → (∃𝑧∃𝑤𝜒 → ∃𝑧∃𝑤(𝜒 ∧ 𝜑))) | 
| 25 | 24 | 2eximdv 1896 | 
. . 3
⊢ (𝜓 → (∃𝑥∃𝑦∃𝑧∃𝑤𝜒 → ∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑))) | 
| 26 | 21, 25 | syl5com 29 | 
. 2
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → (𝜓 → ∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑))) | 
| 27 | 4, 26 | impbid2 143 | 
1
⊢ (((𝐴 ∈ 𝑅 ∧ 𝐵 ∈ 𝑆) ∧ (𝐶 ∈ 𝑅 ∧ 𝐷 ∈ 𝑆)) → (∃𝑥∃𝑦∃𝑧∃𝑤(𝜒 ∧ 𝜑) ↔ 𝜓)) |