| Step | Hyp | Ref
 | Expression | 
| 1 |   | elxp6 6227 | 
. . . . . . 7
⊢ (𝑧 ∈ (𝑆 × 𝑆) ↔ (𝑧 = 〈(1st ‘𝑧), (2nd ‘𝑧)〉 ∧ ((1st
‘𝑧) ∈ 𝑆 ∧ (2nd
‘𝑧) ∈ 𝑆))) | 
| 2 | 1 | biimpi 120 | 
. . . . . 6
⊢ (𝑧 ∈ (𝑆 × 𝑆) → (𝑧 = 〈(1st ‘𝑧), (2nd ‘𝑧)〉 ∧ ((1st
‘𝑧) ∈ 𝑆 ∧ (2nd
‘𝑧) ∈ 𝑆))) | 
| 3 | 2 | adantl 277 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (𝑆 × 𝑆)) → (𝑧 = 〈(1st ‘𝑧), (2nd ‘𝑧)〉 ∧ ((1st
‘𝑧) ∈ 𝑆 ∧ (2nd
‘𝑧) ∈ 𝑆))) | 
| 4 | 3 | simpld 112 | 
. . . 4
⊢ ((𝜑 ∧ 𝑧 ∈ (𝑆 × 𝑆)) → 𝑧 = 〈(1st ‘𝑧), (2nd ‘𝑧)〉) | 
| 5 | 3 | simprd 114 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (𝑆 × 𝑆)) → ((1st ‘𝑧) ∈ 𝑆 ∧ (2nd ‘𝑧) ∈ 𝑆)) | 
| 6 |   | oprssdmm.f | 
. . . . . . . . 9
⊢ (𝜑 → Rel 𝐹) | 
| 7 | 6 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → Rel 𝐹) | 
| 8 |   | eleq2 2260 | 
. . . . . . . . . 10
⊢ (𝑢 = (𝐹‘〈𝑥, 𝑦〉) → (𝑣 ∈ 𝑢 ↔ 𝑣 ∈ (𝐹‘〈𝑥, 𝑦〉))) | 
| 9 | 8 | exbidv 1839 | 
. . . . . . . . 9
⊢ (𝑢 = (𝐹‘〈𝑥, 𝑦〉) → (∃𝑣 𝑣 ∈ 𝑢 ↔ ∃𝑣 𝑣 ∈ (𝐹‘〈𝑥, 𝑦〉))) | 
| 10 |   | oprssdmm.m | 
. . . . . . . . . . 11
⊢ ((𝜑 ∧ 𝑢 ∈ 𝑆) → ∃𝑣 𝑣 ∈ 𝑢) | 
| 11 | 10 | ralrimiva 2570 | 
. . . . . . . . . 10
⊢ (𝜑 → ∀𝑢 ∈ 𝑆 ∃𝑣 𝑣 ∈ 𝑢) | 
| 12 | 11 | adantr 276 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → ∀𝑢 ∈ 𝑆 ∃𝑣 𝑣 ∈ 𝑢) | 
| 13 |   | df-ov 5925 | 
. . . . . . . . . 10
⊢ (𝑥𝐹𝑦) = (𝐹‘〈𝑥, 𝑦〉) | 
| 14 |   | oprssdmm.cl | 
. . . . . . . . . 10
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥𝐹𝑦) ∈ 𝑆) | 
| 15 | 13, 14 | eqeltrrid 2284 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝐹‘〈𝑥, 𝑦〉) ∈ 𝑆) | 
| 16 | 9, 12, 15 | rspcdva 2873 | 
. . . . . . . 8
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → ∃𝑣 𝑣 ∈ (𝐹‘〈𝑥, 𝑦〉)) | 
| 17 |   | relelfvdm 5590 | 
. . . . . . . . . 10
⊢ ((Rel
𝐹 ∧ 𝑣 ∈ (𝐹‘〈𝑥, 𝑦〉)) → 〈𝑥, 𝑦〉 ∈ dom 𝐹) | 
| 18 | 17 | ex 115 | 
. . . . . . . . 9
⊢ (Rel
𝐹 → (𝑣 ∈ (𝐹‘〈𝑥, 𝑦〉) → 〈𝑥, 𝑦〉 ∈ dom 𝐹)) | 
| 19 | 18 | exlimdv 1833 | 
. . . . . . . 8
⊢ (Rel
𝐹 → (∃𝑣 𝑣 ∈ (𝐹‘〈𝑥, 𝑦〉) → 〈𝑥, 𝑦〉 ∈ dom 𝐹)) | 
| 20 | 7, 16, 19 | sylc 62 | 
. . . . . . 7
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → 〈𝑥, 𝑦〉 ∈ dom 𝐹) | 
| 21 | 20 | ralrimivva 2579 | 
. . . . . 6
⊢ (𝜑 → ∀𝑥 ∈ 𝑆 ∀𝑦 ∈ 𝑆 〈𝑥, 𝑦〉 ∈ dom 𝐹) | 
| 22 | 21 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑧 ∈ (𝑆 × 𝑆)) → ∀𝑥 ∈ 𝑆 ∀𝑦 ∈ 𝑆 〈𝑥, 𝑦〉 ∈ dom 𝐹) | 
| 23 |   | opeq1 3808 | 
. . . . . . 7
⊢ (𝑥 = (1st ‘𝑧) → 〈𝑥, 𝑦〉 = 〈(1st ‘𝑧), 𝑦〉) | 
| 24 | 23 | eleq1d 2265 | 
. . . . . 6
⊢ (𝑥 = (1st ‘𝑧) → (〈𝑥, 𝑦〉 ∈ dom 𝐹 ↔ 〈(1st ‘𝑧), 𝑦〉 ∈ dom 𝐹)) | 
| 25 |   | opeq2 3809 | 
. . . . . . 7
⊢ (𝑦 = (2nd ‘𝑧) → 〈(1st
‘𝑧), 𝑦〉 = 〈(1st
‘𝑧), (2nd
‘𝑧)〉) | 
| 26 | 25 | eleq1d 2265 | 
. . . . . 6
⊢ (𝑦 = (2nd ‘𝑧) → (〈(1st
‘𝑧), 𝑦〉 ∈ dom 𝐹 ↔ 〈(1st
‘𝑧), (2nd
‘𝑧)〉 ∈ dom
𝐹)) | 
| 27 | 24, 26 | rspc2va 2882 | 
. . . . 5
⊢
((((1st ‘𝑧) ∈ 𝑆 ∧ (2nd ‘𝑧) ∈ 𝑆) ∧ ∀𝑥 ∈ 𝑆 ∀𝑦 ∈ 𝑆 〈𝑥, 𝑦〉 ∈ dom 𝐹) → 〈(1st ‘𝑧), (2nd ‘𝑧)〉 ∈ dom 𝐹) | 
| 28 | 5, 22, 27 | syl2anc 411 | 
. . . 4
⊢ ((𝜑 ∧ 𝑧 ∈ (𝑆 × 𝑆)) → 〈(1st ‘𝑧), (2nd ‘𝑧)〉 ∈ dom 𝐹) | 
| 29 | 4, 28 | eqeltrd 2273 | 
. . 3
⊢ ((𝜑 ∧ 𝑧 ∈ (𝑆 × 𝑆)) → 𝑧 ∈ dom 𝐹) | 
| 30 | 29 | ex 115 | 
. 2
⊢ (𝜑 → (𝑧 ∈ (𝑆 × 𝑆) → 𝑧 ∈ dom 𝐹)) | 
| 31 | 30 | ssrdv 3189 | 
1
⊢ (𝜑 → (𝑆 × 𝑆) ⊆ dom 𝐹) |