| Step | Hyp | Ref
 | Expression | 
| 1 |   | iseqf1o.4 | 
. . 3
⊢ (𝜑 → 𝑁 ∈ (ℤ≥‘𝑀)) | 
| 2 |   | eluzfz2 10107 | 
. . 3
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑁 ∈ (𝑀...𝑁)) | 
| 3 | 1, 2 | syl 14 | 
. 2
⊢ (𝜑 → 𝑁 ∈ (𝑀...𝑁)) | 
| 4 |   | oveq2 5930 | 
. . . . . . 7
⊢ (𝑤 = 𝑀 → (𝑀...𝑤) = (𝑀...𝑀)) | 
| 5 | 4 | raleqdv 2699 | 
. . . . . 6
⊢ (𝑤 = 𝑀 → (∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀...𝑀)(𝑓‘𝑥) = 𝑥)) | 
| 6 | 5 | 3anbi2d 1328 | 
. . . . 5
⊢ (𝑤 = 𝑀 → ((𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ (𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑀)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 7 | 6 | exbidv 1839 | 
. . . 4
⊢ (𝑤 = 𝑀 → (∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑀)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 8 | 7 | imbi2d 230 | 
. . 3
⊢ (𝑤 = 𝑀 → ((𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ↔ (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑀)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))))) | 
| 9 |   | oveq2 5930 | 
. . . . . . 7
⊢ (𝑤 = 𝑘 → (𝑀...𝑤) = (𝑀...𝑘)) | 
| 10 | 9 | raleqdv 2699 | 
. . . . . 6
⊢ (𝑤 = 𝑘 → (∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥)) | 
| 11 | 10 | 3anbi2d 1328 | 
. . . . 5
⊢ (𝑤 = 𝑘 → ((𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ (𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 12 | 11 | exbidv 1839 | 
. . . 4
⊢ (𝑤 = 𝑘 → (∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 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)))) | 
| 13 | 12 | imbi2d 230 | 
. . 3
⊢ (𝑤 = 𝑘 → ((𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ↔ (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))))) | 
| 14 |   | oveq2 5930 | 
. . . . . . 7
⊢ (𝑤 = (𝑘 + 1) → (𝑀...𝑤) = (𝑀...(𝑘 + 1))) | 
| 15 | 14 | raleqdv 2699 | 
. . . . . 6
⊢ (𝑤 = (𝑘 + 1) → (∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥)) | 
| 16 | 15 | 3anbi2d 1328 | 
. . . . 5
⊢ (𝑤 = (𝑘 + 1) → ((𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ (𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 17 | 16 | exbidv 1839 | 
. . . 4
⊢ (𝑤 = (𝑘 + 1) → (∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 18 | 17 | imbi2d 230 | 
. . 3
⊢ (𝑤 = (𝑘 + 1) → ((𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ↔ (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))))) | 
| 19 |   | oveq2 5930 | 
. . . . . . 7
⊢ (𝑤 = 𝑁 → (𝑀...𝑤) = (𝑀...𝑁)) | 
| 20 | 19 | raleqdv 2699 | 
. . . . . 6
⊢ (𝑤 = 𝑁 → (∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀...𝑁)(𝑓‘𝑥) = 𝑥)) | 
| 21 | 20 | 3anbi2d 1328 | 
. . . . 5
⊢ (𝑤 = 𝑁 → ((𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ (𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑁)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 22 | 21 | exbidv 1839 | 
. . . 4
⊢ (𝑤 = 𝑁 → (∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑁)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 23 | 22 | imbi2d 230 | 
. . 3
⊢ (𝑤 = 𝑁 → ((𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑤)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ↔ (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑁)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))))) | 
| 24 |   | iseqf1o.1 | 
. . . . 5
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) ∈ 𝑆) | 
| 25 |   | iseqf1o.2 | 
. . . . 5
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) = (𝑦 + 𝑥)) | 
| 26 |   | iseqf1o.3 | 
. . . . 5
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆 ∧ 𝑧 ∈ 𝑆)) → ((𝑥 + 𝑦) + 𝑧) = (𝑥 + (𝑦 + 𝑧))) | 
| 27 |   | iseqf1o.6 | 
. . . . 5
⊢ (𝜑 → 𝐹:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 28 |   | iseqf1o.7 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝐺‘𝑥) ∈ 𝑆) | 
| 29 |   | eluzfz1 10106 | 
. . . . . 6
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑀 ∈ (𝑀...𝑁)) | 
| 30 | 1, 29 | syl 14 | 
. . . . 5
⊢ (𝜑 → 𝑀 ∈ (𝑀...𝑁)) | 
| 31 |   | ral0 3552 | 
. . . . . . 7
⊢
∀𝑥 ∈
∅ (𝐹‘𝑥) = 𝑥 | 
| 32 |   | fzo0 10244 | 
. . . . . . . 8
⊢ (𝑀..^𝑀) = ∅ | 
| 33 | 32 | raleqi 2697 | 
. . . . . . 7
⊢
(∀𝑥 ∈
(𝑀..^𝑀)(𝐹‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ ∅ (𝐹‘𝑥) = 𝑥) | 
| 34 | 31, 33 | mpbir 146 | 
. . . . . 6
⊢
∀𝑥 ∈
(𝑀..^𝑀)(𝐹‘𝑥) = 𝑥 | 
| 35 | 34 | a1i 9 | 
. . . . 5
⊢ (𝜑 → ∀𝑥 ∈ (𝑀..^𝑀)(𝐹‘𝑥) = 𝑥) | 
| 36 |   | f1of 5504 | 
. . . . . . . . . 10
⊢ (𝐹:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) → 𝐹:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 37 | 27, 36 | syl 14 | 
. . . . . . . . 9
⊢ (𝜑 → 𝐹:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 38 |   | eluzel2 9606 | 
. . . . . . . . . . 11
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑀 ∈ ℤ) | 
| 39 | 1, 38 | syl 14 | 
. . . . . . . . . 10
⊢ (𝜑 → 𝑀 ∈ ℤ) | 
| 40 |   | eluzelz 9610 | 
. . . . . . . . . . 11
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑁 ∈ ℤ) | 
| 41 | 1, 40 | syl 14 | 
. . . . . . . . . 10
⊢ (𝜑 → 𝑁 ∈ ℤ) | 
| 42 | 39, 41 | fzfigd 10523 | 
. . . . . . . . 9
⊢ (𝜑 → (𝑀...𝑁) ∈ Fin) | 
| 43 |   | fex 5791 | 
. . . . . . . . 9
⊢ ((𝐹:(𝑀...𝑁)⟶(𝑀...𝑁) ∧ (𝑀...𝑁) ∈ Fin) → 𝐹 ∈ V) | 
| 44 | 37, 42, 43 | syl2anc 411 | 
. . . . . . . 8
⊢ (𝜑 → 𝐹 ∈ V) | 
| 45 |   | fveq1 5557 | 
. . . . . . . . . . . . 13
⊢ (𝑓 = 𝐹 → (𝑓‘𝑥) = (𝐹‘𝑥)) | 
| 46 | 45 | fveq2d 5562 | 
. . . . . . . . . . . 12
⊢ (𝑓 = 𝐹 → (𝐺‘(𝑓‘𝑥)) = (𝐺‘(𝐹‘𝑥))) | 
| 47 | 46 | ifeq1d 3578 | 
. . . . . . . . . . 11
⊢ (𝑓 = 𝐹 → if(𝑥 ≤ 𝑁, (𝐺‘(𝑓‘𝑥)), (𝐺‘𝑀)) = if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀))) | 
| 48 | 47 | mpteq2dv 4124 | 
. . . . . . . . . 10
⊢ (𝑓 = 𝐹 → (𝑥 ∈ (ℤ≥‘𝑀) ↦ if(𝑥 ≤ 𝑁, (𝐺‘(𝑓‘𝑥)), (𝐺‘𝑀))) = (𝑥 ∈ (ℤ≥‘𝑀) ↦ if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀)))) | 
| 49 |   | iseqf1o.p | 
. . . . . . . . . 10
⊢ 𝑃 = (𝑥 ∈ (ℤ≥‘𝑀) ↦ if(𝑥 ≤ 𝑁, (𝐺‘(𝑓‘𝑥)), (𝐺‘𝑀))) | 
| 50 |   | iseqf1o.l | 
. . . . . . . . . 10
⊢ 𝐿 = (𝑥 ∈ (ℤ≥‘𝑀) ↦ if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀))) | 
| 51 | 48, 49, 50 | 3eqtr4g 2254 | 
. . . . . . . . 9
⊢ (𝑓 = 𝐹 → 𝑃 = 𝐿) | 
| 52 | 51 | adantl 277 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑓 = 𝐹) → 𝑃 = 𝐿) | 
| 53 | 44, 52 | csbied 3131 | 
. . . . . . 7
⊢ (𝜑 → ⦋𝐹 / 𝑓⦌𝑃 = 𝐿) | 
| 54 | 53 | seqeq3d 10547 | 
. . . . . 6
⊢ (𝜑 → seq𝑀( + , ⦋𝐹 / 𝑓⦌𝑃) = seq𝑀( + , 𝐿)) | 
| 55 | 54 | fveq1d 5560 | 
. . . . 5
⊢ (𝜑 → (seq𝑀( + , ⦋𝐹 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 56 | 24, 25, 26, 1, 27, 28, 30, 27, 35, 55, 49 | seq3f1olemstep 10606 | 
. . . 4
⊢ (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑀)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 57 | 56 | a1i 9 | 
. . 3
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑀)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 58 |   | nfv 1542 | 
. . . . . . . 8
⊢
Ⅎ𝑔(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 59 |   | nfv 1542 | 
. . . . . . . . 9
⊢
Ⅎ𝑓 𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) | 
| 60 |   | nfv 1542 | 
. . . . . . . . 9
⊢
Ⅎ𝑓∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 | 
| 61 |   | nfcv 2339 | 
. . . . . . . . . . . 12
⊢
Ⅎ𝑓𝑀 | 
| 62 |   | nfcv 2339 | 
. . . . . . . . . . . 12
⊢
Ⅎ𝑓
+ | 
| 63 |   | nfcsb1v 3117 | 
. . . . . . . . . . . 12
⊢
Ⅎ𝑓⦋𝑔 / 𝑓⦌𝑃 | 
| 64 | 61, 62, 63 | nfseq 10549 | 
. . . . . . . . . . 11
⊢
Ⅎ𝑓seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃) | 
| 65 |   | nfcv 2339 | 
. . . . . . . . . . 11
⊢
Ⅎ𝑓𝑁 | 
| 66 | 64, 65 | nffv 5568 | 
. . . . . . . . . 10
⊢
Ⅎ𝑓(seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) | 
| 67 | 66 | nfeq1 2349 | 
. . . . . . . . 9
⊢
Ⅎ𝑓(seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁) | 
| 68 | 59, 60, 67 | nf3an 1580 | 
. . . . . . . 8
⊢
Ⅎ𝑓(𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 69 |   | f1oeq1 5492 | 
. . . . . . . . 9
⊢ (𝑓 = 𝑔 → (𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ↔ 𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁))) | 
| 70 |   | fveq1 5557 | 
. . . . . . . . . . 11
⊢ (𝑓 = 𝑔 → (𝑓‘𝑥) = (𝑔‘𝑥)) | 
| 71 | 70 | eqeq1d 2205 | 
. . . . . . . . . 10
⊢ (𝑓 = 𝑔 → ((𝑓‘𝑥) = 𝑥 ↔ (𝑔‘𝑥) = 𝑥)) | 
| 72 | 71 | ralbidv 2497 | 
. . . . . . . . 9
⊢ (𝑓 = 𝑔 → (∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥)) | 
| 73 |   | csbeq1a 3093 | 
. . . . . . . . . . . 12
⊢ (𝑓 = 𝑔 → 𝑃 = ⦋𝑔 / 𝑓⦌𝑃) | 
| 74 | 73 | seqeq3d 10547 | 
. . . . . . . . . . 11
⊢ (𝑓 = 𝑔 → seq𝑀( + , 𝑃) = seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)) | 
| 75 | 74 | fveq1d 5560 | 
. . . . . . . . . 10
⊢ (𝑓 = 𝑔 → (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁)) | 
| 76 | 75 | eqeq1d 2205 | 
. . . . . . . . 9
⊢ (𝑓 = 𝑔 → ((seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁) ↔ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 77 | 69, 72, 76 | 3anbi123d 1323 | 
. . . . . . . 8
⊢ (𝑓 = 𝑔 → ((𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 78 | 58, 68, 77 | cbvex 1770 | 
. . . . . . 7
⊢
(∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ ∃𝑔(𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 79 |   | fveq2 5558 | 
. . . . . . . . . . 11
⊢ (𝑥 = 𝑎 → (𝑔‘𝑥) = (𝑔‘𝑎)) | 
| 80 |   | id 19 | 
. . . . . . . . . . 11
⊢ (𝑥 = 𝑎 → 𝑥 = 𝑎) | 
| 81 | 79, 80 | eqeq12d 2211 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑎 → ((𝑔‘𝑥) = 𝑥 ↔ (𝑔‘𝑎) = 𝑎)) | 
| 82 | 81 | cbvralv 2729 | 
. . . . . . . . 9
⊢
(∀𝑥 ∈
(𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ↔ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎) | 
| 83 | 82 | 3anbi2i 1193 | 
. . . . . . . 8
⊢ ((𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 84 | 83 | exbii 1619 | 
. . . . . . 7
⊢
(∃𝑔(𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ ∃𝑔(𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 85 | 78, 84 | bitri 184 | 
. . . . . 6
⊢
(∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) ↔ ∃𝑔(𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 86 |   | simpll 527 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → 𝜑) | 
| 87 | 86, 24 | sylan 283 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) ∈ 𝑆) | 
| 88 | 86, 25 | sylan 283 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) = (𝑦 + 𝑥)) | 
| 89 | 86, 26 | sylan 283 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆 ∧ 𝑧 ∈ 𝑆)) → ((𝑥 + 𝑦) + 𝑧) = (𝑥 + (𝑦 + 𝑧))) | 
| 90 | 1 | ad2antrr 488 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → 𝑁 ∈ (ℤ≥‘𝑀)) | 
| 91 | 27 | ad2antrr 488 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → 𝐹:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 92 | 86, 28 | sylan 283 | 
. . . . . . . . 9
⊢ ((((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝐺‘𝑥) ∈ 𝑆) | 
| 93 |   | fzofzp1 10303 | 
. . . . . . . . . 10
⊢ (𝑘 ∈ (𝑀..^𝑁) → (𝑘 + 1) ∈ (𝑀...𝑁)) | 
| 94 | 93 | ad2antlr 489 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → (𝑘 + 1) ∈ (𝑀...𝑁)) | 
| 95 |   | simpr1 1005 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → 𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 96 |   | simpr2 1006 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎) | 
| 97 | 96, 82 | sylibr 134 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → ∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥) | 
| 98 |   | elfzoelz 10222 | 
. . . . . . . . . . . 12
⊢ (𝑘 ∈ (𝑀..^𝑁) → 𝑘 ∈ ℤ) | 
| 99 | 98 | ad2antlr 489 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → 𝑘 ∈ ℤ) | 
| 100 |   | fzval3 10280 | 
. . . . . . . . . . . 12
⊢ (𝑘 ∈ ℤ → (𝑀...𝑘) = (𝑀..^(𝑘 + 1))) | 
| 101 | 100 | raleqdv 2699 | 
. . . . . . . . . . 11
⊢ (𝑘 ∈ ℤ →
(∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀..^(𝑘 + 1))(𝑔‘𝑥) = 𝑥)) | 
| 102 | 99, 101 | syl 14 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → (∀𝑥 ∈ (𝑀...𝑘)(𝑔‘𝑥) = 𝑥 ↔ ∀𝑥 ∈ (𝑀..^(𝑘 + 1))(𝑔‘𝑥) = 𝑥)) | 
| 103 | 97, 102 | mpbid 147 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → ∀𝑥 ∈ (𝑀..^(𝑘 + 1))(𝑔‘𝑥) = 𝑥) | 
| 104 |   | simpr3 1007 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) | 
| 105 | 87, 88, 89, 90, 91, 92, 94, 95, 103, 104, 49 | seq3f1olemstep 10606 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) ∧ (𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) | 
| 106 | 105 | ex 115 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) → ((𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 107 | 106 | exlimdv 1833 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) → (∃𝑔(𝑔:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑎 ∈ (𝑀...𝑘)(𝑔‘𝑎) = 𝑎 ∧ (seq𝑀( + , ⦋𝑔 / 𝑓⦌𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 108 | 85, 107 | biimtrid 152 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀..^𝑁)) → (∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 109 | 108 | expcom 116 | 
. . . 4
⊢ (𝑘 ∈ (𝑀..^𝑁) → (𝜑 → (∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)) → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))))) | 
| 110 | 109 | a2d 26 | 
. . 3
⊢ (𝑘 ∈ (𝑀..^𝑁) → ((𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑘)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) → (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...(𝑘 + 1))(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))))) | 
| 111 | 8, 13, 18, 23, 57, 110 | fzind2 10315 | 
. 2
⊢ (𝑁 ∈ (𝑀...𝑁) → (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑁)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁)))) | 
| 112 | 3, 111 | mpcom 36 | 
1
⊢ (𝜑 → ∃𝑓(𝑓:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) ∧ ∀𝑥 ∈ (𝑀...𝑁)(𝑓‘𝑥) = 𝑥 ∧ (seq𝑀( + , 𝑃)‘𝑁) = (seq𝑀( + , 𝐿)‘𝑁))) |