| Step | Hyp | Ref
| Expression |
| 1 | | isupgr.v |
. . . . 5
⊢ 𝑉 = (Vtx‘𝐺) |
| 2 | | isupgr.e |
. . . . 5
⊢ 𝐸 = (iEdg‘𝐺) |
| 3 | 1, 2 | upgr1or2 15747 |
. . . 4
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → ((𝐸‘𝐹) ≈ 1o ∨ (𝐸‘𝐹) ≈ 2o)) |
| 4 | | en1 6901 |
. . . . . . 7
⊢ ((𝐸‘𝐹) ≈ 1o ↔ ∃𝑧(𝐸‘𝐹) = {𝑧}) |
| 5 | | dfsn2 3649 |
. . . . . . . . 9
⊢ {𝑧} = {𝑧, 𝑧} |
| 6 | 5 | eqeq2i 2217 |
. . . . . . . 8
⊢ ((𝐸‘𝐹) = {𝑧} ↔ (𝐸‘𝐹) = {𝑧, 𝑧}) |
| 7 | 6 | exbii 1629 |
. . . . . . 7
⊢
(∃𝑧(𝐸‘𝐹) = {𝑧} ↔ ∃𝑧(𝐸‘𝐹) = {𝑧, 𝑧}) |
| 8 | 4, 7 | bitri 184 |
. . . . . 6
⊢ ((𝐸‘𝐹) ≈ 1o ↔ ∃𝑧(𝐸‘𝐹) = {𝑧, 𝑧}) |
| 9 | | preq2 3713 |
. . . . . . . . . . 11
⊢ (𝑦 = 𝑧 → {𝑧, 𝑦} = {𝑧, 𝑧}) |
| 10 | 9 | eqeq2d 2218 |
. . . . . . . . . 10
⊢ (𝑦 = 𝑧 → ((𝐸‘𝐹) = {𝑧, 𝑦} ↔ (𝐸‘𝐹) = {𝑧, 𝑧})) |
| 11 | 10 | spcegv 2863 |
. . . . . . . . 9
⊢ (𝑧 ∈ V → ((𝐸‘𝐹) = {𝑧, 𝑧} → ∃𝑦(𝐸‘𝐹) = {𝑧, 𝑦})) |
| 12 | 11 | elv 2777 |
. . . . . . . 8
⊢ ((𝐸‘𝐹) = {𝑧, 𝑧} → ∃𝑦(𝐸‘𝐹) = {𝑧, 𝑦}) |
| 13 | | preq1 3712 |
. . . . . . . . . . . 12
⊢ (𝑥 = 𝑧 → {𝑥, 𝑦} = {𝑧, 𝑦}) |
| 14 | 13 | eqeq2d 2218 |
. . . . . . . . . . 11
⊢ (𝑥 = 𝑧 → ((𝐸‘𝐹) = {𝑥, 𝑦} ↔ (𝐸‘𝐹) = {𝑧, 𝑦})) |
| 15 | 14 | exbidv 1849 |
. . . . . . . . . 10
⊢ (𝑥 = 𝑧 → (∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦} ↔ ∃𝑦(𝐸‘𝐹) = {𝑧, 𝑦})) |
| 16 | 15 | spcegv 2863 |
. . . . . . . . 9
⊢ (𝑧 ∈ V → (∃𝑦(𝐸‘𝐹) = {𝑧, 𝑦} → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦})) |
| 17 | 16 | elv 2777 |
. . . . . . . 8
⊢
(∃𝑦(𝐸‘𝐹) = {𝑧, 𝑦} → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦}) |
| 18 | 12, 17 | syl 14 |
. . . . . . 7
⊢ ((𝐸‘𝐹) = {𝑧, 𝑧} → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦}) |
| 19 | 18 | exlimiv 1622 |
. . . . . 6
⊢
(∃𝑧(𝐸‘𝐹) = {𝑧, 𝑧} → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦}) |
| 20 | 8, 19 | sylbi 121 |
. . . . 5
⊢ ((𝐸‘𝐹) ≈ 1o → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦}) |
| 21 | | en2 6923 |
. . . . 5
⊢ ((𝐸‘𝐹) ≈ 2o → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦}) |
| 22 | 20, 21 | jaoi 718 |
. . . 4
⊢ (((𝐸‘𝐹) ≈ 1o ∨ (𝐸‘𝐹) ≈ 2o) → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦}) |
| 23 | 3, 22 | syl 14 |
. . 3
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → ∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦}) |
| 24 | | simp1 1000 |
. . . . . . . . 9
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → 𝐺 ∈ UPGraph) |
| 25 | | simp3 1002 |
. . . . . . . . . 10
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → 𝐹 ∈ 𝐴) |
| 26 | | fndm 5379 |
. . . . . . . . . . 11
⊢ (𝐸 Fn 𝐴 → dom 𝐸 = 𝐴) |
| 27 | 26 | 3ad2ant2 1022 |
. . . . . . . . . 10
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → dom 𝐸 = 𝐴) |
| 28 | 25, 27 | eleqtrrd 2286 |
. . . . . . . . 9
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → 𝐹 ∈ dom 𝐸) |
| 29 | 1, 2 | upgrss 15745 |
. . . . . . . . 9
⊢ ((𝐺 ∈ UPGraph ∧ 𝐹 ∈ dom 𝐸) → (𝐸‘𝐹) ⊆ 𝑉) |
| 30 | 24, 28, 29 | syl2anc 411 |
. . . . . . . 8
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → (𝐸‘𝐹) ⊆ 𝑉) |
| 31 | 30 | adantr 276 |
. . . . . . 7
⊢ (((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}) → (𝐸‘𝐹) ⊆ 𝑉) |
| 32 | | vex 2776 |
. . . . . . . . 9
⊢ 𝑥 ∈ V |
| 33 | 32 | prid1 3741 |
. . . . . . . 8
⊢ 𝑥 ∈ {𝑥, 𝑦} |
| 34 | | simpr 110 |
. . . . . . . 8
⊢ (((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}) → (𝐸‘𝐹) = {𝑥, 𝑦}) |
| 35 | 33, 34 | eleqtrrid 2296 |
. . . . . . 7
⊢ (((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}) → 𝑥 ∈ (𝐸‘𝐹)) |
| 36 | 31, 35 | sseldd 3196 |
. . . . . 6
⊢ (((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}) → 𝑥 ∈ 𝑉) |
| 37 | | vex 2776 |
. . . . . . . . 9
⊢ 𝑦 ∈ V |
| 38 | 37 | prid2 3742 |
. . . . . . . 8
⊢ 𝑦 ∈ {𝑥, 𝑦} |
| 39 | 38, 34 | eleqtrrid 2296 |
. . . . . . 7
⊢ (((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}) → 𝑦 ∈ (𝐸‘𝐹)) |
| 40 | 31, 39 | sseldd 3196 |
. . . . . 6
⊢ (((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}) → 𝑦 ∈ 𝑉) |
| 41 | 36, 40, 34 | jca31 309 |
. . . . 5
⊢ (((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}) → ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) ∧ (𝐸‘𝐹) = {𝑥, 𝑦})) |
| 42 | 41 | ex 115 |
. . . 4
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → ((𝐸‘𝐹) = {𝑥, 𝑦} → ((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}))) |
| 43 | 42 | 2eximdv 1906 |
. . 3
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → (∃𝑥∃𝑦(𝐸‘𝐹) = {𝑥, 𝑦} → ∃𝑥∃𝑦((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) ∧ (𝐸‘𝐹) = {𝑥, 𝑦}))) |
| 44 | 23, 43 | mpd 13 |
. 2
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → ∃𝑥∃𝑦((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) ∧ (𝐸‘𝐹) = {𝑥, 𝑦})) |
| 45 | | r2ex 2527 |
. 2
⊢
(∃𝑥 ∈
𝑉 ∃𝑦 ∈ 𝑉 (𝐸‘𝐹) = {𝑥, 𝑦} ↔ ∃𝑥∃𝑦((𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉) ∧ (𝐸‘𝐹) = {𝑥, 𝑦})) |
| 46 | 44, 45 | sylibr 134 |
1
⊢ ((𝐺 ∈ UPGraph ∧ 𝐸 Fn 𝐴 ∧ 𝐹 ∈ 𝐴) → ∃𝑥 ∈ 𝑉 ∃𝑦 ∈ 𝑉 (𝐸‘𝐹) = {𝑥, 𝑦}) |