| Step | Hyp | Ref
 | Expression | 
| 1 |   | df-tpos 6303 | 
. . 3
⊢ tpos
𝐹 = (𝐹 ∘ (𝑥 ∈ (◡dom 𝐹 ∪ {∅}) ↦ ∪ ◡{𝑥})) | 
| 2 |   | relcnv 5047 | 
. . . . . . 7
⊢ Rel ◡dom 𝐹 | 
| 3 |   | df-rel 4670 | 
. . . . . . 7
⊢ (Rel
◡dom 𝐹 ↔ ◡dom 𝐹 ⊆ (V × V)) | 
| 4 | 2, 3 | mpbi 145 | 
. . . . . 6
⊢ ◡dom 𝐹 ⊆ (V × V) | 
| 5 |   | unss1 3332 | 
. . . . . 6
⊢ (◡dom 𝐹 ⊆ (V × V) → (◡dom 𝐹 ∪ {∅}) ⊆ ((V × V)
∪ {∅})) | 
| 6 |   | resmpt 4994 | 
. . . . . 6
⊢ ((◡dom 𝐹 ∪ {∅}) ⊆ ((V × V)
∪ {∅}) → ((𝑥
∈ ((V × V) ∪ {∅}) ↦ ∪
◡{𝑥}) ↾ (◡dom 𝐹 ∪ {∅})) = (𝑥 ∈ (◡dom 𝐹 ∪ {∅}) ↦ ∪ ◡{𝑥})) | 
| 7 | 4, 5, 6 | mp2b 8 | 
. . . . 5
⊢ ((𝑥 ∈ ((V × V) ∪
{∅}) ↦ ∪ ◡{𝑥}) ↾ (◡dom 𝐹 ∪ {∅})) = (𝑥 ∈ (◡dom 𝐹 ∪ {∅}) ↦ ∪ ◡{𝑥}) | 
| 8 |   | resss 4970 | 
. . . . 5
⊢ ((𝑥 ∈ ((V × V) ∪
{∅}) ↦ ∪ ◡{𝑥}) ↾ (◡dom 𝐹 ∪ {∅})) ⊆ (𝑥 ∈ ((V × V) ∪
{∅}) ↦ ∪ ◡{𝑥}) | 
| 9 | 7, 8 | eqsstrri 3216 | 
. . . 4
⊢ (𝑥 ∈ (◡dom 𝐹 ∪ {∅}) ↦ ∪ ◡{𝑥}) ⊆ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥}) | 
| 10 |   | coss2 4822 | 
. . . 4
⊢ ((𝑥 ∈ (◡dom 𝐹 ∪ {∅}) ↦ ∪ ◡{𝑥}) ⊆ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥}) → (𝐹 ∘ (𝑥 ∈ (◡dom 𝐹 ∪ {∅}) ↦ ∪ ◡{𝑥})) ⊆ (𝐹 ∘ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥}))) | 
| 11 | 9, 10 | ax-mp 5 | 
. . 3
⊢ (𝐹 ∘ (𝑥 ∈ (◡dom 𝐹 ∪ {∅}) ↦ ∪ ◡{𝑥})) ⊆ (𝐹 ∘ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})) | 
| 12 | 1, 11 | eqsstri 3215 | 
. 2
⊢ tpos
𝐹 ⊆ (𝐹 ∘ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})) | 
| 13 |   | relco 5168 | 
. . 3
⊢ Rel
(𝐹 ∘ (𝑥 ∈ ((V × V) ∪
{∅}) ↦ ∪ ◡{𝑥})) | 
| 14 |   | vex 2766 | 
. . . . 5
⊢ 𝑦 ∈ V | 
| 15 |   | vex 2766 | 
. . . . 5
⊢ 𝑧 ∈ V | 
| 16 | 14, 15 | opelco 4838 | 
. . . 4
⊢
(〈𝑦, 𝑧〉 ∈ (𝐹 ∘ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})) ↔ ∃𝑤(𝑦(𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})𝑤 ∧ 𝑤𝐹𝑧)) | 
| 17 |   | vex 2766 | 
. . . . . . . . 9
⊢ 𝑤 ∈ V | 
| 18 |   | eleq1 2259 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑦 → (𝑥 ∈ ((V × V) ∪ {∅})
↔ 𝑦 ∈ ((V ×
V) ∪ {∅}))) | 
| 19 |   | sneq 3633 | 
. . . . . . . . . . . . 13
⊢ (𝑥 = 𝑦 → {𝑥} = {𝑦}) | 
| 20 | 19 | cnveqd 4842 | 
. . . . . . . . . . . 12
⊢ (𝑥 = 𝑦 → ◡{𝑥} = ◡{𝑦}) | 
| 21 | 20 | unieqd 3850 | 
. . . . . . . . . . 11
⊢ (𝑥 = 𝑦 → ∪ ◡{𝑥} = ∪ ◡{𝑦}) | 
| 22 | 21 | eqeq2d 2208 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑦 → (𝑧 = ∪ ◡{𝑥} ↔ 𝑧 = ∪ ◡{𝑦})) | 
| 23 | 18, 22 | anbi12d 473 | 
. . . . . . . . 9
⊢ (𝑥 = 𝑦 → ((𝑥 ∈ ((V × V) ∪ {∅}) ∧
𝑧 = ∪ ◡{𝑥}) ↔ (𝑦 ∈ ((V × V) ∪ {∅}) ∧
𝑧 = ∪ ◡{𝑦}))) | 
| 24 |   | eqeq1 2203 | 
. . . . . . . . . 10
⊢ (𝑧 = 𝑤 → (𝑧 = ∪ ◡{𝑦} ↔ 𝑤 = ∪ ◡{𝑦})) | 
| 25 | 24 | anbi2d 464 | 
. . . . . . . . 9
⊢ (𝑧 = 𝑤 → ((𝑦 ∈ ((V × V) ∪ {∅}) ∧
𝑧 = ∪ ◡{𝑦}) ↔ (𝑦 ∈ ((V × V) ∪ {∅}) ∧
𝑤 = ∪ ◡{𝑦}))) | 
| 26 |   | df-mpt 4096 | 
. . . . . . . . 9
⊢ (𝑥 ∈ ((V × V) ∪
{∅}) ↦ ∪ ◡{𝑥}) = {〈𝑥, 𝑧〉 ∣ (𝑥 ∈ ((V × V) ∪ {∅}) ∧
𝑧 = ∪ ◡{𝑥})} | 
| 27 | 14, 17, 23, 25, 26 | brab 4307 | 
. . . . . . . 8
⊢ (𝑦(𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})𝑤 ↔ (𝑦 ∈ ((V × V) ∪ {∅}) ∧
𝑤 = ∪ ◡{𝑦})) | 
| 28 |   | simplr 528 | 
. . . . . . . . . . . 12
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → 𝑤 = ∪ ◡{𝑦}) | 
| 29 | 17, 15 | breldm 4870 | 
. . . . . . . . . . . . 13
⊢ (𝑤𝐹𝑧 → 𝑤 ∈ dom 𝐹) | 
| 30 | 29 | adantl 277 | 
. . . . . . . . . . . 12
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → 𝑤 ∈ dom 𝐹) | 
| 31 | 28, 30 | eqeltrrd 2274 | 
. . . . . . . . . . 11
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → ∪ ◡{𝑦} ∈ dom 𝐹) | 
| 32 |   | elvv 4725 | 
. . . . . . . . . . . . . 14
⊢ (𝑦 ∈ (V × V) ↔
∃𝑧∃𝑤 𝑦 = 〈𝑧, 𝑤〉) | 
| 33 |   | opswapg 5156 | 
. . . . . . . . . . . . . . . . . . 19
⊢ ((𝑧 ∈ V ∧ 𝑤 ∈ V) → ∪ ◡{〈𝑧, 𝑤〉} = 〈𝑤, 𝑧〉) | 
| 34 | 15, 17, 33 | mp2an 426 | 
. . . . . . . . . . . . . . . . . 18
⊢ ∪ ◡{〈𝑧, 𝑤〉} = 〈𝑤, 𝑧〉 | 
| 35 | 34 | eleq1i 2262 | 
. . . . . . . . . . . . . . . . 17
⊢ (∪ ◡{〈𝑧, 𝑤〉} ∈ dom 𝐹 ↔ 〈𝑤, 𝑧〉 ∈ dom 𝐹) | 
| 36 | 15, 17 | opelcnv 4848 | 
. . . . . . . . . . . . . . . . 17
⊢
(〈𝑧, 𝑤〉 ∈ ◡dom 𝐹 ↔ 〈𝑤, 𝑧〉 ∈ dom 𝐹) | 
| 37 | 35, 36 | bitr4i 187 | 
. . . . . . . . . . . . . . . 16
⊢ (∪ ◡{〈𝑧, 𝑤〉} ∈ dom 𝐹 ↔ 〈𝑧, 𝑤〉 ∈ ◡dom 𝐹) | 
| 38 |   | sneq 3633 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ (𝑦 = 〈𝑧, 𝑤〉 → {𝑦} = {〈𝑧, 𝑤〉}) | 
| 39 | 38 | cnveqd 4842 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑦 = 〈𝑧, 𝑤〉 → ◡{𝑦} = ◡{〈𝑧, 𝑤〉}) | 
| 40 | 39 | unieqd 3850 | 
. . . . . . . . . . . . . . . . . 18
⊢ (𝑦 = 〈𝑧, 𝑤〉 → ∪
◡{𝑦} = ∪ ◡{〈𝑧, 𝑤〉}) | 
| 41 | 40 | eleq1d 2265 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝑦 = 〈𝑧, 𝑤〉 → (∪
◡{𝑦} ∈ dom 𝐹 ↔ ∪ ◡{〈𝑧, 𝑤〉} ∈ dom 𝐹)) | 
| 42 |   | eleq1 2259 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝑦 = 〈𝑧, 𝑤〉 → (𝑦 ∈ ◡dom 𝐹 ↔ 〈𝑧, 𝑤〉 ∈ ◡dom 𝐹)) | 
| 43 | 41, 42 | bibi12d 235 | 
. . . . . . . . . . . . . . . 16
⊢ (𝑦 = 〈𝑧, 𝑤〉 → ((∪
◡{𝑦} ∈ dom 𝐹 ↔ 𝑦 ∈ ◡dom 𝐹) ↔ (∪ ◡{〈𝑧, 𝑤〉} ∈ dom 𝐹 ↔ 〈𝑧, 𝑤〉 ∈ ◡dom 𝐹))) | 
| 44 | 37, 43 | mpbiri 168 | 
. . . . . . . . . . . . . . 15
⊢ (𝑦 = 〈𝑧, 𝑤〉 → (∪
◡{𝑦} ∈ dom 𝐹 ↔ 𝑦 ∈ ◡dom 𝐹)) | 
| 45 | 44 | exlimivv 1911 | 
. . . . . . . . . . . . . 14
⊢
(∃𝑧∃𝑤 𝑦 = 〈𝑧, 𝑤〉 → (∪
◡{𝑦} ∈ dom 𝐹 ↔ 𝑦 ∈ ◡dom 𝐹)) | 
| 46 | 32, 45 | sylbi 121 | 
. . . . . . . . . . . . 13
⊢ (𝑦 ∈ (V × V) →
(∪ ◡{𝑦} ∈ dom 𝐹 ↔ 𝑦 ∈ ◡dom 𝐹)) | 
| 47 | 46 | biimpcd 159 | 
. . . . . . . . . . . 12
⊢ (∪ ◡{𝑦} ∈ dom 𝐹 → (𝑦 ∈ (V × V) → 𝑦 ∈ ◡dom 𝐹)) | 
| 48 |   | elun1 3330 | 
. . . . . . . . . . . 12
⊢ (𝑦 ∈ ◡dom 𝐹 → 𝑦 ∈ (◡dom 𝐹 ∪ {∅})) | 
| 49 | 47, 48 | syl6 33 | 
. . . . . . . . . . 11
⊢ (∪ ◡{𝑦} ∈ dom 𝐹 → (𝑦 ∈ (V × V) → 𝑦 ∈ (◡dom 𝐹 ∪ {∅}))) | 
| 50 | 31, 49 | syl 14 | 
. . . . . . . . . 10
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → (𝑦 ∈ (V × V) → 𝑦 ∈ (◡dom 𝐹 ∪ {∅}))) | 
| 51 |   | elun2 3331 | 
. . . . . . . . . . 11
⊢ (𝑦 ∈ {∅} → 𝑦 ∈ (◡dom 𝐹 ∪ {∅})) | 
| 52 | 51 | a1i 9 | 
. . . . . . . . . 10
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → (𝑦 ∈ {∅} → 𝑦 ∈ (◡dom 𝐹 ∪ {∅}))) | 
| 53 |   | simpll 527 | 
. . . . . . . . . . 11
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → 𝑦 ∈ ((V × V) ∪
{∅})) | 
| 54 |   | elun 3304 | 
. . . . . . . . . . 11
⊢ (𝑦 ∈ ((V × V) ∪
{∅}) ↔ (𝑦 ∈
(V × V) ∨ 𝑦 ∈
{∅})) | 
| 55 | 53, 54 | sylib 122 | 
. . . . . . . . . 10
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → (𝑦 ∈ (V × V) ∨ 𝑦 ∈ {∅})) | 
| 56 | 50, 52, 55 | mpjaod 719 | 
. . . . . . . . 9
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → 𝑦 ∈ (◡dom 𝐹 ∪ {∅})) | 
| 57 |   | simpr 110 | 
. . . . . . . . . 10
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → 𝑤𝐹𝑧) | 
| 58 | 28, 57 | eqbrtrrd 4057 | 
. . . . . . . . 9
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → ∪ ◡{𝑦}𝐹𝑧) | 
| 59 | 56, 58 | jca 306 | 
. . . . . . . 8
⊢ (((𝑦 ∈ ((V × V) ∪
{∅}) ∧ 𝑤 = ∪ ◡{𝑦}) ∧ 𝑤𝐹𝑧) → (𝑦 ∈ (◡dom 𝐹 ∪ {∅}) ∧ ∪ ◡{𝑦}𝐹𝑧)) | 
| 60 | 27, 59 | sylanb 284 | 
. . . . . . 7
⊢ ((𝑦(𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})𝑤 ∧ 𝑤𝐹𝑧) → (𝑦 ∈ (◡dom 𝐹 ∪ {∅}) ∧ ∪ ◡{𝑦}𝐹𝑧)) | 
| 61 |   | brtpos2 6309 | 
. . . . . . . 8
⊢ (𝑧 ∈ V → (𝑦tpos 𝐹𝑧 ↔ (𝑦 ∈ (◡dom 𝐹 ∪ {∅}) ∧ ∪ ◡{𝑦}𝐹𝑧))) | 
| 62 | 15, 61 | ax-mp 5 | 
. . . . . . 7
⊢ (𝑦tpos 𝐹𝑧 ↔ (𝑦 ∈ (◡dom 𝐹 ∪ {∅}) ∧ ∪ ◡{𝑦}𝐹𝑧)) | 
| 63 | 60, 62 | sylibr 134 | 
. . . . . 6
⊢ ((𝑦(𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})𝑤 ∧ 𝑤𝐹𝑧) → 𝑦tpos 𝐹𝑧) | 
| 64 |   | df-br 4034 | 
. . . . . 6
⊢ (𝑦tpos 𝐹𝑧 ↔ 〈𝑦, 𝑧〉 ∈ tpos 𝐹) | 
| 65 | 63, 64 | sylib 122 | 
. . . . 5
⊢ ((𝑦(𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})𝑤 ∧ 𝑤𝐹𝑧) → 〈𝑦, 𝑧〉 ∈ tpos 𝐹) | 
| 66 | 65 | exlimiv 1612 | 
. . . 4
⊢
(∃𝑤(𝑦(𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})𝑤 ∧ 𝑤𝐹𝑧) → 〈𝑦, 𝑧〉 ∈ tpos 𝐹) | 
| 67 | 16, 66 | sylbi 121 | 
. . 3
⊢
(〈𝑦, 𝑧〉 ∈ (𝐹 ∘ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})) → 〈𝑦, 𝑧〉 ∈ tpos 𝐹) | 
| 68 | 13, 67 | relssi 4754 | 
. 2
⊢ (𝐹 ∘ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})) ⊆ tpos 𝐹 | 
| 69 | 12, 68 | eqssi 3199 | 
1
⊢ tpos
𝐹 = (𝐹 ∘ (𝑥 ∈ ((V × V) ∪ {∅})
↦ ∪ ◡{𝑥})) |