| Step | Hyp | Ref
 | Expression | 
| 1 |   | iseqf1olemstep.j | 
. . . . . 6
⊢ (𝜑 → 𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 2 |   | f1of 5504 | 
. . . . . 6
⊢ (𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) → 𝐽:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 3 | 1, 2 | syl 14 | 
. . . . 5
⊢ (𝜑 → 𝐽:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 4 |   | iseqf1olemstep.k | 
. . . . . . 7
⊢ (𝜑 → 𝐾 ∈ (𝑀...𝑁)) | 
| 5 |   | elfzel1 10099 | 
. . . . . . 7
⊢ (𝐾 ∈ (𝑀...𝑁) → 𝑀 ∈ ℤ) | 
| 6 | 4, 5 | syl 14 | 
. . . . . 6
⊢ (𝜑 → 𝑀 ∈ ℤ) | 
| 7 |   | elfzel2 10098 | 
. . . . . . 7
⊢ (𝐾 ∈ (𝑀...𝑁) → 𝑁 ∈ ℤ) | 
| 8 | 4, 7 | syl 14 | 
. . . . . 6
⊢ (𝜑 → 𝑁 ∈ ℤ) | 
| 9 | 6, 8 | fzfigd 10523 | 
. . . . 5
⊢ (𝜑 → (𝑀...𝑁) ∈ Fin) | 
| 10 |   | fex 5791 | 
. . . . 5
⊢ ((𝐽:(𝑀...𝑁)⟶(𝑀...𝑁) ∧ (𝑀...𝑁) ∈ Fin) → 𝐽 ∈ V) | 
| 11 | 3, 9, 10 | syl2anc 411 | 
. . . 4
⊢ (𝜑 → 𝐽 ∈ V) | 
| 12 | 11 | adantr 276 | 
. . 3
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → 𝐽 ∈ V) | 
| 13 | 1 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → 𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 14 |   | iseqf1olemstep.const | 
. . . . . . 7
⊢ (𝜑 → ∀𝑥 ∈ (𝑀..^𝐾)(𝐽‘𝑥) = 𝑥) | 
| 15 | 14 | adantr 276 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → ∀𝑥 ∈ (𝑀..^𝐾)(𝐽‘𝑥) = 𝑥) | 
| 16 |   | eqcom 2198 | 
. . . . . . . . . 10
⊢ (𝐾 = (◡𝐽‘𝐾) ↔ (◡𝐽‘𝐾) = 𝐾) | 
| 17 | 16 | biimpi 120 | 
. . . . . . . . 9
⊢ (𝐾 = (◡𝐽‘𝐾) → (◡𝐽‘𝐾) = 𝐾) | 
| 18 | 17 | adantl 277 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → (◡𝐽‘𝐾) = 𝐾) | 
| 19 |   | f1ocnvfvb 5827 | 
. . . . . . . . . 10
⊢ ((𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ 𝐾 ∈ (𝑀...𝑁) ∧ 𝐾 ∈ (𝑀...𝑁)) → ((𝐽‘𝐾) = 𝐾 ↔ (◡𝐽‘𝐾) = 𝐾)) | 
| 20 | 1, 4, 4, 19 | syl3anc 1249 | 
. . . . . . . . 9
⊢ (𝜑 → ((𝐽‘𝐾) = 𝐾 ↔ (◡𝐽‘𝐾) = 𝐾)) | 
| 21 | 20 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → ((𝐽‘𝐾) = 𝐾 ↔ (◡𝐽‘𝐾) = 𝐾)) | 
| 22 | 18, 21 | mpbird 167 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → (𝐽‘𝐾) = 𝐾) | 
| 23 |   | elfzelz 10100 | 
. . . . . . . . . 10
⊢ (𝐾 ∈ (𝑀...𝑁) → 𝐾 ∈ ℤ) | 
| 24 | 4, 23 | syl 14 | 
. . . . . . . . 9
⊢ (𝜑 → 𝐾 ∈ ℤ) | 
| 25 | 24 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → 𝐾 ∈ ℤ) | 
| 26 |   | fveq2 5558 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝐾 → (𝐽‘𝑥) = (𝐽‘𝐾)) | 
| 27 |   | id 19 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝐾 → 𝑥 = 𝐾) | 
| 28 | 26, 27 | eqeq12d 2211 | 
. . . . . . . . 9
⊢ (𝑥 = 𝐾 → ((𝐽‘𝑥) = 𝑥 ↔ (𝐽‘𝐾) = 𝐾)) | 
| 29 | 28 | ralsng 3662 | 
. . . . . . . 8
⊢ (𝐾 ∈ ℤ →
(∀𝑥 ∈ {𝐾} (𝐽‘𝑥) = 𝑥 ↔ (𝐽‘𝐾) = 𝐾)) | 
| 30 | 25, 29 | syl 14 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → (∀𝑥 ∈ {𝐾} (𝐽‘𝑥) = 𝑥 ↔ (𝐽‘𝐾) = 𝐾)) | 
| 31 | 22, 30 | mpbird 167 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → ∀𝑥 ∈ {𝐾} (𝐽‘𝑥) = 𝑥) | 
| 32 |   | ralun 3345 | 
. . . . . 6
⊢
((∀𝑥 ∈
(𝑀..^𝐾)(𝐽‘𝑥) = 𝑥 ∧ ∀𝑥 ∈ {𝐾} (𝐽‘𝑥) = 𝑥) → ∀𝑥 ∈ ((𝑀..^𝐾) ∪ {𝐾})(𝐽‘𝑥) = 𝑥) | 
| 33 | 15, 31, 32 | syl2anc 411 | 
. . . . 5
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → ∀𝑥 ∈ ((𝑀..^𝐾) ∪ {𝐾})(𝐽‘𝑥) = 𝑥) | 
| 34 |   | elfzuz 10096 | 
. . . . . . . 8
⊢ (𝐾 ∈ (𝑀...𝑁) → 𝐾 ∈ (ℤ≥‘𝑀)) | 
| 35 |   | fzisfzounsn 10312 | 
. . . . . . . 8
⊢ (𝐾 ∈
(ℤ≥‘𝑀) → (𝑀...𝐾) = ((𝑀..^𝐾) ∪ {𝐾})) | 
| 36 | 4, 34, 35 | 3syl 17 | 
. . . . . . 7
⊢ (𝜑 → (𝑀...𝐾) = ((𝑀..^𝐾) ∪ {𝐾})) | 
| 37 | 36 | raleqdv 2699 | 
. . . . . 6
⊢ (𝜑 → (∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ ((𝑀..^𝐾) ∪ {𝐾})(𝐽‘𝑥) = 𝑥)) | 
| 38 | 37 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → (∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ ((𝑀..^𝐾) ∪ {𝐾})(𝐽‘𝑥) = 𝑥)) | 
| 39 | 33, 38 | mpbird 167 | 
. . . 4
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → ∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥) | 
| 40 |   | seq3f1olemstep.jp | 
. . . . 5
⊢ (𝜑 → (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 41 | 40 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 42 | 13, 39, 41 | 3jca 1179 | 
. . 3
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → (𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 43 |   | nfcv 2339 | 
. . . 4
⊢
Ⅎ𝑓𝐽 | 
| 44 |   | nfv 1542 | 
. . . . 5
⊢
Ⅎ𝑓 𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) | 
| 45 |   | nfv 1542 | 
. . . . 5
⊢
Ⅎ𝑓∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥 | 
| 46 |   | nfcv 2339 | 
. . . . . . . 8
⊢
Ⅎ𝑓𝑀 | 
| 47 |   | nfcv 2339 | 
. . . . . . . 8
⊢
Ⅎ𝑓
+ | 
| 48 |   | nfcsb1v 3117 | 
. . . . . . . 8
⊢
Ⅎ𝑓⦋𝐽 / 𝑓⦌𝑃 | 
| 49 | 46, 47, 48 | nfseq 10549 | 
. . . . . . 7
⊢
Ⅎ𝑓seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃) | 
| 50 |   | nfcv 2339 | 
. . . . . . 7
⊢
Ⅎ𝑓𝑁 | 
| 51 | 49, 50 | nffv 5568 | 
. . . . . 6
⊢
Ⅎ𝑓(seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) | 
| 52 | 51 | nfeq1 2349 | 
. . . . 5
⊢
Ⅎ𝑓(seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁) | 
| 53 | 44, 45, 52 | nf3an 1580 | 
. . . 4
⊢
Ⅎ𝑓(𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 54 |   | f1oeq1 5492 | 
. . . . 5
⊢ (𝑓 = 𝐽 → (𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ↔ 𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁))) | 
| 55 |   | fveq1 5557 | 
. . . . . . 7
⊢ (𝑓 = 𝐽 → (𝑓‘𝑥) = (𝐽‘𝑥)) | 
| 56 | 55 | eqeq1d 2205 | 
. . . . . 6
⊢ (𝑓 = 𝐽 → ((𝑓‘𝑥) = 𝑥 ↔ (𝐽‘𝑥) = 𝑥)) | 
| 57 | 56 | ralbidv 2497 | 
. . . . 5
⊢ (𝑓 = 𝐽 → (∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥)) | 
| 58 |   | csbeq1a 3093 | 
. . . . . . . 8
⊢ (𝑓 = 𝐽 → 𝑃 = ⦋𝐽 / 𝑓⦌𝑃) | 
| 59 | 58 | seqeq3d 10547 | 
. . . . . . 7
⊢ (𝑓 = 𝐽 → seq𝑀( + , 𝑃) = seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)) | 
| 60 | 59 | fveq1d 5560 | 
. . . . . 6
⊢ (𝑓 = 𝐽 → (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁)) | 
| 61 | 60 | eqeq1d 2205 | 
. . . . 5
⊢ (𝑓 = 𝐽 → ((seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁) ↔ (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 62 | 54, 57, 61 | 3anbi123d 1323 | 
. . . 4
⊢ (𝑓 = 𝐽 → ((𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ (𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 63 | 43, 53, 62 | spcegf 2847 | 
. . 3
⊢ (𝐽 ∈ V → ((𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝐽‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 64 | 12, 42, 63 | sylc 62 | 
. 2
⊢ ((𝜑 ∧ 𝐾 = (◡𝐽‘𝐾)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 65 | 4 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → 𝐾 ∈ (𝑀...𝑁)) | 
| 66 | 1 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → 𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 67 |   | eqid 2196 | 
. . . 4
⊢ (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) | 
| 68 | 65, 66, 67 | iseqf1olemqf1o 10598 | 
. . 3
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))):(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 69 | 14 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → ∀𝑥 ∈ (𝑀..^𝐾)(𝐽‘𝑥) = 𝑥) | 
| 70 | 65, 66, 67, 69 | iseqf1olemqk 10599 | 
. . 3
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → ∀𝑥 ∈ (𝑀...𝐾)((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥) | 
| 71 |   | iseqf1o.1 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) ∈ 𝑆) | 
| 72 | 71 | adantlr 477 | 
. . . . 5
⊢ (((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) ∈ 𝑆) | 
| 73 |   | iseqf1o.2 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) = (𝑦 + 𝑥)) | 
| 74 | 73 | adantlr 477 | 
. . . . 5
⊢ (((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) = (𝑦 + 𝑥)) | 
| 75 |   | iseqf1o.3 | 
. . . . . 6
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆 ∧ 𝑧 ∈ 𝑆)) → ((𝑥 + 𝑦) + 𝑧) = (𝑥 + (𝑦 + 𝑧))) | 
| 76 | 75 | adantlr 477 | 
. . . . 5
⊢ (((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆 ∧ 𝑧 ∈ 𝑆)) → ((𝑥 + 𝑦) + 𝑧) = (𝑥 + (𝑦 + 𝑧))) | 
| 77 |   | iseqf1o.4 | 
. . . . . 6
⊢ (𝜑 → 𝑁 ∈ (ℤ≥‘𝑀)) | 
| 78 | 77 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → 𝑁 ∈ (ℤ≥‘𝑀)) | 
| 79 |   | iseqf1o.6 | 
. . . . . 6
⊢ (𝜑 → 𝐹:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 80 | 79 | adantr 276 | 
. . . . 5
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → 𝐹:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 81 |   | iseqf1o.7 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝐺‘𝑥) ∈ 𝑆) | 
| 82 | 81 | adantlr 477 | 
. . . . 5
⊢ (((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝐺‘𝑥) ∈ 𝑆) | 
| 83 |   | neqne 2375 | 
. . . . . 6
⊢ (¬
𝐾 = (◡𝐽‘𝐾) → 𝐾 ≠ (◡𝐽‘𝐾)) | 
| 84 | 83 | adantl 277 | 
. . . . 5
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → 𝐾 ≠ (◡𝐽‘𝐾)) | 
| 85 |   | seq3f1olemstep.p | 
. . . . 5
⊢ 𝑃 = (𝑥 ∈ (ℤ≥‘𝑀) ↦ if(𝑥 ≤ 𝑁, (𝐺‘(𝑓‘𝑥)), (𝐺‘𝑀))) | 
| 86 | 72, 74, 76, 78, 80, 82, 65, 66, 69, 84, 67, 85 | seq3f1olemqsum 10605 | 
. . . 4
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁)) | 
| 87 | 40 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → (seq𝑀( + , ⦋𝐽 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 88 | 86, 87 | eqtr3d 2231 | 
. . 3
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 89 | 65, 5 | syl 14 | 
. . . . 5
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → 𝑀 ∈ ℤ) | 
| 90 | 65, 7 | syl 14 | 
. . . . 5
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → 𝑁 ∈ ℤ) | 
| 91 | 89, 90 | fzfigd 10523 | 
. . . 4
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → (𝑀...𝑁) ∈ Fin) | 
| 92 |   | mptexg 5787 | 
. . . 4
⊢ ((𝑀...𝑁) ∈ Fin → (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) ∈ V) | 
| 93 |   | nfcv 2339 | 
. . . . 5
⊢
Ⅎ𝑓(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) | 
| 94 |   | nfv 1542 | 
. . . . . 6
⊢
Ⅎ𝑓(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))):(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) | 
| 95 |   | nfv 1542 | 
. . . . . 6
⊢
Ⅎ𝑓∀𝑥 ∈ (𝑀...𝐾)((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥 | 
| 96 |   | nfcsb1v 3117 | 
. . . . . . . . 9
⊢
Ⅎ𝑓⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃 | 
| 97 | 46, 47, 96 | nfseq 10549 | 
. . . . . . . 8
⊢
Ⅎ𝑓seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃) | 
| 98 | 97, 50 | nffv 5568 | 
. . . . . . 7
⊢
Ⅎ𝑓(seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) | 
| 99 | 98 | nfeq1 2349 | 
. . . . . 6
⊢
Ⅎ𝑓(seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁) | 
| 100 | 94, 95, 99 | nf3an 1580 | 
. . . . 5
⊢
Ⅎ𝑓((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))):(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 101 |   | f1oeq1 5492 | 
. . . . . 6
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → (𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ↔ (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))):(𝑀...𝑁)–1-1-onto→(𝑀...𝑁))) | 
| 102 |   | fveq1 5557 | 
. . . . . . . 8
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → (𝑓‘𝑥) = ((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥)) | 
| 103 | 102 | eqeq1d 2205 | 
. . . . . . 7
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → ((𝑓‘𝑥) = 𝑥 ↔ ((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥)) | 
| 104 | 103 | ralbidv 2497 | 
. . . . . 6
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → (∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀...𝐾)((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥)) | 
| 105 |   | csbeq1a 3093 | 
. . . . . . . . 9
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → 𝑃 = ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃) | 
| 106 | 105 | seqeq3d 10547 | 
. . . . . . . 8
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → seq𝑀( + , 𝑃) = seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)) | 
| 107 | 106 | fveq1d 5560 | 
. . . . . . 7
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁)) | 
| 108 | 107 | eqeq1d 2205 | 
. . . . . 6
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → ((seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁) ↔ (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 109 | 101, 104,
108 | 3anbi123d 1323 | 
. . . . 5
⊢ (𝑓 = (𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) → ((𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ ((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))):(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 110 | 93, 100, 109 | spcegf 2847 | 
. . . 4
⊢ ((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) ∈ V → (((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))):(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 111 | 91, 92, 110 | 3syl 17 | 
. . 3
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → (((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))):(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)((𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢)))‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋(𝑢 ∈ (𝑀...𝑁) ↦ if(𝑢 ∈ (𝐾...(◡𝐽‘𝐾)), if(𝑢 = 𝐾, 𝐾, (𝐽‘(𝑢 − 1))), (𝐽‘𝑢))) / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 112 | 68, 70, 88, 111 | mp3and 1351 | 
. 2
⊢ ((𝜑 ∧ ¬ 𝐾 = (◡𝐽‘𝐾)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 113 |   | f1ocnv 5517 | 
. . . . . . 7
⊢ (𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) → ◡𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 114 |   | f1of 5504 | 
. . . . . . 7
⊢ (◡𝐽:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) → ◡𝐽:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 115 | 1, 113, 114 | 3syl 17 | 
. . . . . 6
⊢ (𝜑 → ◡𝐽:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 116 | 115, 4 | ffvelcdmd 5698 | 
. . . . 5
⊢ (𝜑 → (◡𝐽‘𝐾) ∈ (𝑀...𝑁)) | 
| 117 |   | elfzelz 10100 | 
. . . . 5
⊢ ((◡𝐽‘𝐾) ∈ (𝑀...𝑁) → (◡𝐽‘𝐾) ∈ ℤ) | 
| 118 | 116, 117 | syl 14 | 
. . . 4
⊢ (𝜑 → (◡𝐽‘𝐾) ∈ ℤ) | 
| 119 |   | zdceq 9401 | 
. . . 4
⊢ ((𝐾 ∈ ℤ ∧ (◡𝐽‘𝐾) ∈ ℤ) →
DECID 𝐾 =
(◡𝐽‘𝐾)) | 
| 120 | 24, 118, 119 | syl2anc 411 | 
. . 3
⊢ (𝜑 → DECID 𝐾 = (◡𝐽‘𝐾)) | 
| 121 |   | exmiddc 837 | 
. . 3
⊢
(DECID 𝐾 = (◡𝐽‘𝐾) → (𝐾 = (◡𝐽‘𝐾) ∨ ¬ 𝐾 = (◡𝐽‘𝐾))) | 
| 122 | 120, 121 | syl 14 | 
. 2
⊢ (𝜑 → (𝐾 = (◡𝐽‘𝐾) ∨ ¬ 𝐾 = (◡𝐽‘𝐾))) | 
| 123 | 64, 112, 122 | mpjaodan 799 | 
1
⊢ (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝐾)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) |