| Step | Hyp | Ref
| Expression |
| 1 | | 0ss 4382 |
. . . . . . . 8
⊢ ∅
⊆ 𝐵 |
| 2 | | sspsstr 4090 |
. . . . . . . 8
⊢ ((∅
⊆ 𝐵 ∧ 𝐵 ⊊ 𝐴) → ∅ ⊊ 𝐴) |
| 3 | 1, 2 | mpan 690 |
. . . . . . 7
⊢ (𝐵 ⊊ 𝐴 → ∅ ⊊ 𝐴) |
| 4 | | 0pss 4429 |
. . . . . . . 8
⊢ (∅
⊊ 𝐴 ↔ 𝐴 ≠ ∅) |
| 5 | | df-ne 2932 |
. . . . . . . 8
⊢ (𝐴 ≠ ∅ ↔ ¬ 𝐴 = ∅) |
| 6 | 4, 5 | bitri 275 |
. . . . . . 7
⊢ (∅
⊊ 𝐴 ↔ ¬
𝐴 =
∅) |
| 7 | 3, 6 | sylib 218 |
. . . . . 6
⊢ (𝐵 ⊊ 𝐴 → ¬ 𝐴 = ∅) |
| 8 | | nn0suc 7899 |
. . . . . . 7
⊢ (𝐴 ∈ ω → (𝐴 = ∅ ∨ ∃𝑥 ∈ ω 𝐴 = suc 𝑥)) |
| 9 | 8 | orcanai 1004 |
. . . . . 6
⊢ ((𝐴 ∈ ω ∧ ¬
𝐴 = ∅) →
∃𝑥 ∈ ω
𝐴 = suc 𝑥) |
| 10 | 7, 9 | sylan2 593 |
. . . . 5
⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊊ 𝐴) → ∃𝑥 ∈ ω 𝐴 = suc 𝑥) |
| 11 | | pssnel 4453 |
. . . . . . . . . 10
⊢ (𝐵 ⊊ suc 𝑥 → ∃𝑦(𝑦 ∈ suc 𝑥 ∧ ¬ 𝑦 ∈ 𝐵)) |
| 12 | | pssss 4080 |
. . . . . . . . . . . . . . . . 17
⊢ (𝐵 ⊊ suc 𝑥 → 𝐵 ⊆ suc 𝑥) |
| 13 | | ssdif 4126 |
. . . . . . . . . . . . . . . . . 18
⊢ (𝐵 ⊆ suc 𝑥 → (𝐵 ∖ {𝑦}) ⊆ (suc 𝑥 ∖ {𝑦})) |
| 14 | | disjsn 4693 |
. . . . . . . . . . . . . . . . . . . 20
⊢ ((𝐵 ∩ {𝑦}) = ∅ ↔ ¬ 𝑦 ∈ 𝐵) |
| 15 | | disj3 4436 |
. . . . . . . . . . . . . . . . . . . 20
⊢ ((𝐵 ∩ {𝑦}) = ∅ ↔ 𝐵 = (𝐵 ∖ {𝑦})) |
| 16 | 14, 15 | bitr3i 277 |
. . . . . . . . . . . . . . . . . . 19
⊢ (¬
𝑦 ∈ 𝐵 ↔ 𝐵 = (𝐵 ∖ {𝑦})) |
| 17 | | sseq1 3991 |
. . . . . . . . . . . . . . . . . . 19
⊢ (𝐵 = (𝐵 ∖ {𝑦}) → (𝐵 ⊆ (suc 𝑥 ∖ {𝑦}) ↔ (𝐵 ∖ {𝑦}) ⊆ (suc 𝑥 ∖ {𝑦}))) |
| 18 | 16, 17 | sylbi 217 |
. . . . . . . . . . . . . . . . . 18
⊢ (¬
𝑦 ∈ 𝐵 → (𝐵 ⊆ (suc 𝑥 ∖ {𝑦}) ↔ (𝐵 ∖ {𝑦}) ⊆ (suc 𝑥 ∖ {𝑦}))) |
| 19 | 13, 18 | imbitrrid 246 |
. . . . . . . . . . . . . . . . 17
⊢ (¬
𝑦 ∈ 𝐵 → (𝐵 ⊆ suc 𝑥 → 𝐵 ⊆ (suc 𝑥 ∖ {𝑦}))) |
| 20 | | vex 3468 |
. . . . . . . . . . . . . . . . . . . 20
⊢ 𝑥 ∈ V |
| 21 | 20 | sucex 7809 |
. . . . . . . . . . . . . . . . . . 19
⊢ suc 𝑥 ∈ V |
| 22 | 21 | difexi 5312 |
. . . . . . . . . . . . . . . . . 18
⊢ (suc
𝑥 ∖ {𝑦}) ∈ V |
| 23 | | ssdomg 9023 |
. . . . . . . . . . . . . . . . . 18
⊢ ((suc
𝑥 ∖ {𝑦}) ∈ V → (𝐵 ⊆ (suc 𝑥 ∖ {𝑦}) → 𝐵 ≼ (suc 𝑥 ∖ {𝑦}))) |
| 24 | 22, 23 | ax-mp 5 |
. . . . . . . . . . . . . . . . 17
⊢ (𝐵 ⊆ (suc 𝑥 ∖ {𝑦}) → 𝐵 ≼ (suc 𝑥 ∖ {𝑦})) |
| 25 | 12, 19, 24 | syl56 36 |
. . . . . . . . . . . . . . . 16
⊢ (¬
𝑦 ∈ 𝐵 → (𝐵 ⊊ suc 𝑥 → 𝐵 ≼ (suc 𝑥 ∖ {𝑦}))) |
| 26 | 25 | imp 406 |
. . . . . . . . . . . . . . 15
⊢ ((¬
𝑦 ∈ 𝐵 ∧ 𝐵 ⊊ suc 𝑥) → 𝐵 ≼ (suc 𝑥 ∖ {𝑦})) |
| 27 | | vex 3468 |
. . . . . . . . . . . . . . . . 17
⊢ 𝑦 ∈ V |
| 28 | 20, 27 | phplem3OLD 9239 |
. . . . . . . . . . . . . . . 16
⊢ ((𝑥 ∈ ω ∧ 𝑦 ∈ suc 𝑥) → 𝑥 ≈ (suc 𝑥 ∖ {𝑦})) |
| 29 | 28 | ensymd 9028 |
. . . . . . . . . . . . . . 15
⊢ ((𝑥 ∈ ω ∧ 𝑦 ∈ suc 𝑥) → (suc 𝑥 ∖ {𝑦}) ≈ 𝑥) |
| 30 | | domentr 9036 |
. . . . . . . . . . . . . . 15
⊢ ((𝐵 ≼ (suc 𝑥 ∖ {𝑦}) ∧ (suc 𝑥 ∖ {𝑦}) ≈ 𝑥) → 𝐵 ≼ 𝑥) |
| 31 | 26, 29, 30 | syl2an 596 |
. . . . . . . . . . . . . 14
⊢ (((¬
𝑦 ∈ 𝐵 ∧ 𝐵 ⊊ suc 𝑥) ∧ (𝑥 ∈ ω ∧ 𝑦 ∈ suc 𝑥)) → 𝐵 ≼ 𝑥) |
| 32 | 31 | exp43 436 |
. . . . . . . . . . . . 13
⊢ (¬
𝑦 ∈ 𝐵 → (𝐵 ⊊ suc 𝑥 → (𝑥 ∈ ω → (𝑦 ∈ suc 𝑥 → 𝐵 ≼ 𝑥)))) |
| 33 | 32 | com4r 94 |
. . . . . . . . . . . 12
⊢ (𝑦 ∈ suc 𝑥 → (¬ 𝑦 ∈ 𝐵 → (𝐵 ⊊ suc 𝑥 → (𝑥 ∈ ω → 𝐵 ≼ 𝑥)))) |
| 34 | 33 | imp 406 |
. . . . . . . . . . 11
⊢ ((𝑦 ∈ suc 𝑥 ∧ ¬ 𝑦 ∈ 𝐵) → (𝐵 ⊊ suc 𝑥 → (𝑥 ∈ ω → 𝐵 ≼ 𝑥))) |
| 35 | 34 | exlimiv 1929 |
. . . . . . . . . 10
⊢
(∃𝑦(𝑦 ∈ suc 𝑥 ∧ ¬ 𝑦 ∈ 𝐵) → (𝐵 ⊊ suc 𝑥 → (𝑥 ∈ ω → 𝐵 ≼ 𝑥))) |
| 36 | 11, 35 | mpcom 38 |
. . . . . . . . 9
⊢ (𝐵 ⊊ suc 𝑥 → (𝑥 ∈ ω → 𝐵 ≼ 𝑥)) |
| 37 | | endomtr 9035 |
. . . . . . . . . . . 12
⊢ ((suc
𝑥 ≈ 𝐵 ∧ 𝐵 ≼ 𝑥) → suc 𝑥 ≼ 𝑥) |
| 38 | | sssucid 6445 |
. . . . . . . . . . . . 13
⊢ 𝑥 ⊆ suc 𝑥 |
| 39 | | ssdomg 9023 |
. . . . . . . . . . . . 13
⊢ (suc
𝑥 ∈ V → (𝑥 ⊆ suc 𝑥 → 𝑥 ≼ suc 𝑥)) |
| 40 | 21, 38, 39 | mp2 9 |
. . . . . . . . . . . 12
⊢ 𝑥 ≼ suc 𝑥 |
| 41 | | sbth 9116 |
. . . . . . . . . . . 12
⊢ ((suc
𝑥 ≼ 𝑥 ∧ 𝑥 ≼ suc 𝑥) → suc 𝑥 ≈ 𝑥) |
| 42 | 37, 40, 41 | sylancl 586 |
. . . . . . . . . . 11
⊢ ((suc
𝑥 ≈ 𝐵 ∧ 𝐵 ≼ 𝑥) → suc 𝑥 ≈ 𝑥) |
| 43 | 42 | expcom 413 |
. . . . . . . . . 10
⊢ (𝐵 ≼ 𝑥 → (suc 𝑥 ≈ 𝐵 → suc 𝑥 ≈ 𝑥)) |
| 44 | | peano2b 7887 |
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ ω ↔ suc 𝑥 ∈
ω) |
| 45 | | nnord 7878 |
. . . . . . . . . . . . 13
⊢ (suc
𝑥 ∈ ω → Ord
suc 𝑥) |
| 46 | 44, 45 | sylbi 217 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ ω → Ord suc
𝑥) |
| 47 | 20 | sucid 6447 |
. . . . . . . . . . . 12
⊢ 𝑥 ∈ suc 𝑥 |
| 48 | | nordeq 6384 |
. . . . . . . . . . . 12
⊢ ((Ord suc
𝑥 ∧ 𝑥 ∈ suc 𝑥) → suc 𝑥 ≠ 𝑥) |
| 49 | 46, 47, 48 | sylancl 586 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ ω → suc 𝑥 ≠ 𝑥) |
| 50 | | nneneqOLD 9241 |
. . . . . . . . . . . . . 14
⊢ ((suc
𝑥 ∈ ω ∧
𝑥 ∈ ω) →
(suc 𝑥 ≈ 𝑥 ↔ suc 𝑥 = 𝑥)) |
| 51 | 44, 50 | sylanb 581 |
. . . . . . . . . . . . 13
⊢ ((𝑥 ∈ ω ∧ 𝑥 ∈ ω) → (suc
𝑥 ≈ 𝑥 ↔ suc 𝑥 = 𝑥)) |
| 52 | 51 | anidms 566 |
. . . . . . . . . . . 12
⊢ (𝑥 ∈ ω → (suc
𝑥 ≈ 𝑥 ↔ suc 𝑥 = 𝑥)) |
| 53 | 52 | necon3bbid 2968 |
. . . . . . . . . . 11
⊢ (𝑥 ∈ ω → (¬
suc 𝑥 ≈ 𝑥 ↔ suc 𝑥 ≠ 𝑥)) |
| 54 | 49, 53 | mpbird 257 |
. . . . . . . . . 10
⊢ (𝑥 ∈ ω → ¬ suc
𝑥 ≈ 𝑥) |
| 55 | 43, 54 | nsyli 157 |
. . . . . . . . 9
⊢ (𝐵 ≼ 𝑥 → (𝑥 ∈ ω → ¬ suc 𝑥 ≈ 𝐵)) |
| 56 | 36, 55 | syli 39 |
. . . . . . . 8
⊢ (𝐵 ⊊ suc 𝑥 → (𝑥 ∈ ω → ¬ suc 𝑥 ≈ 𝐵)) |
| 57 | 56 | com12 32 |
. . . . . . 7
⊢ (𝑥 ∈ ω → (𝐵 ⊊ suc 𝑥 → ¬ suc 𝑥 ≈ 𝐵)) |
| 58 | | psseq2 4073 |
. . . . . . . 8
⊢ (𝐴 = suc 𝑥 → (𝐵 ⊊ 𝐴 ↔ 𝐵 ⊊ suc 𝑥)) |
| 59 | | breq1 5128 |
. . . . . . . . 9
⊢ (𝐴 = suc 𝑥 → (𝐴 ≈ 𝐵 ↔ suc 𝑥 ≈ 𝐵)) |
| 60 | 59 | notbid 318 |
. . . . . . . 8
⊢ (𝐴 = suc 𝑥 → (¬ 𝐴 ≈ 𝐵 ↔ ¬ suc 𝑥 ≈ 𝐵)) |
| 61 | 58, 60 | imbi12d 344 |
. . . . . . 7
⊢ (𝐴 = suc 𝑥 → ((𝐵 ⊊ 𝐴 → ¬ 𝐴 ≈ 𝐵) ↔ (𝐵 ⊊ suc 𝑥 → ¬ suc 𝑥 ≈ 𝐵))) |
| 62 | 57, 61 | syl5ibrcom 247 |
. . . . . 6
⊢ (𝑥 ∈ ω → (𝐴 = suc 𝑥 → (𝐵 ⊊ 𝐴 → ¬ 𝐴 ≈ 𝐵))) |
| 63 | 62 | rexlimiv 3135 |
. . . . 5
⊢
(∃𝑥 ∈
ω 𝐴 = suc 𝑥 → (𝐵 ⊊ 𝐴 → ¬ 𝐴 ≈ 𝐵)) |
| 64 | 10, 63 | syl 17 |
. . . 4
⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊊ 𝐴) → (𝐵 ⊊ 𝐴 → ¬ 𝐴 ≈ 𝐵)) |
| 65 | 64 | ex 412 |
. . 3
⊢ (𝐴 ∈ ω → (𝐵 ⊊ 𝐴 → (𝐵 ⊊ 𝐴 → ¬ 𝐴 ≈ 𝐵))) |
| 66 | 65 | pm2.43d 53 |
. 2
⊢ (𝐴 ∈ ω → (𝐵 ⊊ 𝐴 → ¬ 𝐴 ≈ 𝐵)) |
| 67 | 66 | imp 406 |
1
⊢ ((𝐴 ∈ ω ∧ 𝐵 ⊊ 𝐴) → ¬ 𝐴 ≈ 𝐵) |