| Step | Hyp | Ref
 | Expression | 
| 1 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = 𝐶 → (𝑥 +o 𝐴) = (𝐶 +o 𝐴)) | 
| 2 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = 𝐶 → (𝑥 +o 𝐵) = (𝐶 +o 𝐵)) | 
| 3 | 1, 2 | sseq12d 3214 | 
. . . . . 6
⊢ (𝑥 = 𝐶 → ((𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵) ↔ (𝐶 +o 𝐴) ⊆ (𝐶 +o 𝐵))) | 
| 4 | 3 | bibi2d 232 | 
. . . . 5
⊢ (𝑥 = 𝐶 → ((𝐴 ⊆ 𝐵 ↔ (𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵)) ↔ (𝐴 ⊆ 𝐵 ↔ (𝐶 +o 𝐴) ⊆ (𝐶 +o 𝐵)))) | 
| 5 | 4 | imbi2d 230 | 
. . . 4
⊢ (𝑥 = 𝐶 → (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ (𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵))) ↔ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ (𝐶 +o 𝐴) ⊆ (𝐶 +o 𝐵))))) | 
| 6 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = ∅ → (𝑥 +o 𝐴) = (∅ +o 𝐴)) | 
| 7 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = ∅ → (𝑥 +o 𝐵) = (∅ +o 𝐵)) | 
| 8 | 6, 7 | sseq12d 3214 | 
. . . . . 6
⊢ (𝑥 = ∅ → ((𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵) ↔ (∅ +o 𝐴) ⊆ (∅ +o
𝐵))) | 
| 9 | 8 | bibi2d 232 | 
. . . . 5
⊢ (𝑥 = ∅ → ((𝐴 ⊆ 𝐵 ↔ (𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵)) ↔ (𝐴 ⊆ 𝐵 ↔ (∅ +o 𝐴) ⊆ (∅ +o
𝐵)))) | 
| 10 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = 𝑦 → (𝑥 +o 𝐴) = (𝑦 +o 𝐴)) | 
| 11 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = 𝑦 → (𝑥 +o 𝐵) = (𝑦 +o 𝐵)) | 
| 12 | 10, 11 | sseq12d 3214 | 
. . . . . 6
⊢ (𝑥 = 𝑦 → ((𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵) ↔ (𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵))) | 
| 13 | 12 | bibi2d 232 | 
. . . . 5
⊢ (𝑥 = 𝑦 → ((𝐴 ⊆ 𝐵 ↔ (𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵)) ↔ (𝐴 ⊆ 𝐵 ↔ (𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵)))) | 
| 14 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = suc 𝑦 → (𝑥 +o 𝐴) = (suc 𝑦 +o 𝐴)) | 
| 15 |   | oveq1 5929 | 
. . . . . . 7
⊢ (𝑥 = suc 𝑦 → (𝑥 +o 𝐵) = (suc 𝑦 +o 𝐵)) | 
| 16 | 14, 15 | sseq12d 3214 | 
. . . . . 6
⊢ (𝑥 = suc 𝑦 → ((𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵) ↔ (suc 𝑦 +o 𝐴) ⊆ (suc 𝑦 +o 𝐵))) | 
| 17 | 16 | bibi2d 232 | 
. . . . 5
⊢ (𝑥 = suc 𝑦 → ((𝐴 ⊆ 𝐵 ↔ (𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵)) ↔ (𝐴 ⊆ 𝐵 ↔ (suc 𝑦 +o 𝐴) ⊆ (suc 𝑦 +o 𝐵)))) | 
| 18 |   | nna0r 6536 | 
. . . . . . . 8
⊢ (𝐴 ∈ ω → (∅
+o 𝐴) = 𝐴) | 
| 19 | 18 | eqcomd 2202 | 
. . . . . . 7
⊢ (𝐴 ∈ ω → 𝐴 = (∅ +o 𝐴)) | 
| 20 | 19 | adantr 276 | 
. . . . . 6
⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → 𝐴 = (∅ +o 𝐴)) | 
| 21 |   | nna0r 6536 | 
. . . . . . . 8
⊢ (𝐵 ∈ ω → (∅
+o 𝐵) = 𝐵) | 
| 22 | 21 | eqcomd 2202 | 
. . . . . . 7
⊢ (𝐵 ∈ ω → 𝐵 = (∅ +o 𝐵)) | 
| 23 | 22 | adantl 277 | 
. . . . . 6
⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → 𝐵 = (∅ +o 𝐵)) | 
| 24 | 20, 23 | sseq12d 3214 | 
. . . . 5
⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ (∅ +o 𝐴) ⊆ (∅ +o
𝐵))) | 
| 25 |   | nnacl 6538 | 
. . . . . . . . . . 11
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω) → (𝑦 +o 𝐴) ∈ ω) | 
| 26 | 25 | 3adant3 1019 | 
. . . . . . . . . 10
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝑦 +o 𝐴) ∈ ω) | 
| 27 |   | nnacl 6538 | 
. . . . . . . . . . 11
⊢ ((𝑦 ∈ ω ∧ 𝐵 ∈ ω) → (𝑦 +o 𝐵) ∈ ω) | 
| 28 | 27 | 3adant2 1018 | 
. . . . . . . . . 10
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝑦 +o 𝐵) ∈ ω) | 
| 29 |   | nnsucsssuc 6550 | 
. . . . . . . . . 10
⊢ (((𝑦 +o 𝐴) ∈ ω ∧ (𝑦 +o 𝐵) ∈ ω) → ((𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵) ↔ suc (𝑦 +o 𝐴) ⊆ suc (𝑦 +o 𝐵))) | 
| 30 | 26, 28, 29 | syl2anc 411 | 
. . . . . . . . 9
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵) ↔ suc (𝑦 +o 𝐴) ⊆ suc (𝑦 +o 𝐵))) | 
| 31 |   | nnasuc 6534 | 
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ω ∧ 𝑦 ∈ ω) → (𝐴 +o suc 𝑦) = suc (𝐴 +o 𝑦)) | 
| 32 |   | peano2 4631 | 
. . . . . . . . . . . . . 14
⊢ (𝑦 ∈ ω → suc 𝑦 ∈
ω) | 
| 33 |   | nnacom 6542 | 
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ ω ∧ suc 𝑦 ∈ ω) → (𝐴 +o suc 𝑦) = (suc 𝑦 +o 𝐴)) | 
| 34 | 32, 33 | sylan2 286 | 
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ω ∧ 𝑦 ∈ ω) → (𝐴 +o suc 𝑦) = (suc 𝑦 +o 𝐴)) | 
| 35 |   | nnacom 6542 | 
. . . . . . . . . . . . . 14
⊢ ((𝐴 ∈ ω ∧ 𝑦 ∈ ω) → (𝐴 +o 𝑦) = (𝑦 +o 𝐴)) | 
| 36 |   | suceq 4437 | 
. . . . . . . . . . . . . 14
⊢ ((𝐴 +o 𝑦) = (𝑦 +o 𝐴) → suc (𝐴 +o 𝑦) = suc (𝑦 +o 𝐴)) | 
| 37 | 35, 36 | syl 14 | 
. . . . . . . . . . . . 13
⊢ ((𝐴 ∈ ω ∧ 𝑦 ∈ ω) → suc
(𝐴 +o 𝑦) = suc (𝑦 +o 𝐴)) | 
| 38 | 31, 34, 37 | 3eqtr3rd 2238 | 
. . . . . . . . . . . 12
⊢ ((𝐴 ∈ ω ∧ 𝑦 ∈ ω) → suc
(𝑦 +o 𝐴) = (suc 𝑦 +o 𝐴)) | 
| 39 | 38 | ancoms 268 | 
. . . . . . . . . . 11
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω) → suc
(𝑦 +o 𝐴) = (suc 𝑦 +o 𝐴)) | 
| 40 | 39 | 3adant3 1019 | 
. . . . . . . . . 10
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → suc
(𝑦 +o 𝐴) = (suc 𝑦 +o 𝐴)) | 
| 41 |   | nnasuc 6534 | 
. . . . . . . . . . . . 13
⊢ ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐵 +o suc 𝑦) = suc (𝐵 +o 𝑦)) | 
| 42 |   | nnacom 6542 | 
. . . . . . . . . . . . . 14
⊢ ((𝐵 ∈ ω ∧ suc 𝑦 ∈ ω) → (𝐵 +o suc 𝑦) = (suc 𝑦 +o 𝐵)) | 
| 43 | 32, 42 | sylan2 286 | 
. . . . . . . . . . . . 13
⊢ ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐵 +o suc 𝑦) = (suc 𝑦 +o 𝐵)) | 
| 44 |   | nnacom 6542 | 
. . . . . . . . . . . . . 14
⊢ ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → (𝐵 +o 𝑦) = (𝑦 +o 𝐵)) | 
| 45 |   | suceq 4437 | 
. . . . . . . . . . . . . 14
⊢ ((𝐵 +o 𝑦) = (𝑦 +o 𝐵) → suc (𝐵 +o 𝑦) = suc (𝑦 +o 𝐵)) | 
| 46 | 44, 45 | syl 14 | 
. . . . . . . . . . . . 13
⊢ ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → suc
(𝐵 +o 𝑦) = suc (𝑦 +o 𝐵)) | 
| 47 | 41, 43, 46 | 3eqtr3rd 2238 | 
. . . . . . . . . . . 12
⊢ ((𝐵 ∈ ω ∧ 𝑦 ∈ ω) → suc
(𝑦 +o 𝐵) = (suc 𝑦 +o 𝐵)) | 
| 48 | 47 | ancoms 268 | 
. . . . . . . . . . 11
⊢ ((𝑦 ∈ ω ∧ 𝐵 ∈ ω) → suc
(𝑦 +o 𝐵) = (suc 𝑦 +o 𝐵)) | 
| 49 | 48 | 3adant2 1018 | 
. . . . . . . . . 10
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → suc
(𝑦 +o 𝐵) = (suc 𝑦 +o 𝐵)) | 
| 50 | 40, 49 | sseq12d 3214 | 
. . . . . . . . 9
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (suc
(𝑦 +o 𝐴) ⊆ suc (𝑦 +o 𝐵) ↔ (suc 𝑦 +o 𝐴) ⊆ (suc 𝑦 +o 𝐵))) | 
| 51 | 30, 50 | bitrd 188 | 
. . . . . . . 8
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵) ↔ (suc 𝑦 +o 𝐴) ⊆ (suc 𝑦 +o 𝐵))) | 
| 52 | 51 | bibi2d 232 | 
. . . . . . 7
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ⊆ 𝐵 ↔ (𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵)) ↔ (𝐴 ⊆ 𝐵 ↔ (suc 𝑦 +o 𝐴) ⊆ (suc 𝑦 +o 𝐵)))) | 
| 53 | 52 | biimpd 144 | 
. . . . . 6
⊢ ((𝑦 ∈ ω ∧ 𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ⊆ 𝐵 ↔ (𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵)) → (𝐴 ⊆ 𝐵 ↔ (suc 𝑦 +o 𝐴) ⊆ (suc 𝑦 +o 𝐵)))) | 
| 54 | 53 | 3expib 1208 | 
. . . . 5
⊢ (𝑦 ∈ ω → ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → ((𝐴 ⊆ 𝐵 ↔ (𝑦 +o 𝐴) ⊆ (𝑦 +o 𝐵)) → (𝐴 ⊆ 𝐵 ↔ (suc 𝑦 +o 𝐴) ⊆ (suc 𝑦 +o 𝐵))))) | 
| 55 | 9, 13, 17, 24, 54 | finds2 4637 | 
. . . 4
⊢ (𝑥 ∈ ω → ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ (𝑥 +o 𝐴) ⊆ (𝑥 +o 𝐵)))) | 
| 56 | 5, 55 | vtoclga 2830 | 
. . 3
⊢ (𝐶 ∈ ω → ((𝐴 ∈ ω ∧ 𝐵 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ (𝐶 +o 𝐴) ⊆ (𝐶 +o 𝐵)))) | 
| 57 | 56 | impcom 125 | 
. 2
⊢ (((𝐴 ∈ ω ∧ 𝐵 ∈ ω) ∧ 𝐶 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ (𝐶 +o 𝐴) ⊆ (𝐶 +o 𝐵))) | 
| 58 | 57 | 3impa 1196 | 
1
⊢ ((𝐴 ∈ ω ∧ 𝐵 ∈ ω ∧ 𝐶 ∈ ω) → (𝐴 ⊆ 𝐵 ↔ (𝐶 +o 𝐴) ⊆ (𝐶 +o 𝐵))) |