| Step | Hyp | Ref
 | Expression | 
| 1 |   | iseqf1o.4 | 
. . 3
⊢ (𝜑 → 𝑁 ∈ (ℤ≥‘𝑀)) | 
| 2 |   | elfzle2 10103 | 
. . . . . 6
⊢ (𝑘 ∈ (𝑀...𝑁) → 𝑘 ≤ 𝑁) | 
| 3 | 2 | iftrued 3568 | 
. . . . 5
⊢ (𝑘 ∈ (𝑀...𝑁) → if(𝑘 ≤ 𝑁, (𝐺‘(𝐹‘𝑘)), (𝐺‘𝑀)) = (𝐺‘(𝐹‘𝑘))) | 
| 4 | 3 | adantl 277 | 
. . . 4
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → if(𝑘 ≤ 𝑁, (𝐺‘(𝐹‘𝑘)), (𝐺‘𝑀)) = (𝐺‘(𝐹‘𝑘))) | 
| 5 |   | elfzuz 10096 | 
. . . . 5
⊢ (𝑘 ∈ (𝑀...𝑁) → 𝑘 ∈ (ℤ≥‘𝑀)) | 
| 6 |   | fveq2 5558 | 
. . . . . . . 8
⊢ (𝑥 = (𝐹‘𝑘) → (𝐺‘𝑥) = (𝐺‘(𝐹‘𝑘))) | 
| 7 | 6 | eleq1d 2265 | 
. . . . . . 7
⊢ (𝑥 = (𝐹‘𝑘) → ((𝐺‘𝑥) ∈ 𝑆 ↔ (𝐺‘(𝐹‘𝑘)) ∈ 𝑆)) | 
| 8 |   | iseqf1o.7 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝐺‘𝑥) ∈ 𝑆) | 
| 9 | 8 | ralrimiva 2570 | 
. . . . . . . 8
⊢ (𝜑 → ∀𝑥 ∈ (ℤ≥‘𝑀)(𝐺‘𝑥) ∈ 𝑆) | 
| 10 | 9 | adantr 276 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → ∀𝑥 ∈ (ℤ≥‘𝑀)(𝐺‘𝑥) ∈ 𝑆) | 
| 11 |   | iseqf1o.6 | 
. . . . . . . . . 10
⊢ (𝜑 → 𝐹:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁)) | 
| 12 |   | f1of 5504 | 
. . . . . . . . . 10
⊢ (𝐹:(𝑀...𝑁)–1-1-onto→(𝑀...𝑁) → 𝐹:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 13 | 11, 12 | syl 14 | 
. . . . . . . . 9
⊢ (𝜑 → 𝐹:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 14 | 13 | ffvelcdmda 5697 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → (𝐹‘𝑘) ∈ (𝑀...𝑁)) | 
| 15 |   | elfzuz 10096 | 
. . . . . . . 8
⊢ ((𝐹‘𝑘) ∈ (𝑀...𝑁) → (𝐹‘𝑘) ∈ (ℤ≥‘𝑀)) | 
| 16 | 14, 15 | syl 14 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → (𝐹‘𝑘) ∈ (ℤ≥‘𝑀)) | 
| 17 | 7, 10, 16 | rspcdva 2873 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → (𝐺‘(𝐹‘𝑘)) ∈ 𝑆) | 
| 18 | 4, 17 | eqeltrd 2273 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → if(𝑘 ≤ 𝑁, (𝐺‘(𝐹‘𝑘)), (𝐺‘𝑀)) ∈ 𝑆) | 
| 19 |   | breq1 4036 | 
. . . . . . 7
⊢ (𝑎 = 𝑘 → (𝑎 ≤ 𝑁 ↔ 𝑘 ≤ 𝑁)) | 
| 20 |   | 2fveq3 5563 | 
. . . . . . 7
⊢ (𝑎 = 𝑘 → (𝐺‘(𝐹‘𝑎)) = (𝐺‘(𝐹‘𝑘))) | 
| 21 | 19, 20 | ifbieq1d 3583 | 
. . . . . 6
⊢ (𝑎 = 𝑘 → if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)) = if(𝑘 ≤ 𝑁, (𝐺‘(𝐹‘𝑘)), (𝐺‘𝑀))) | 
| 22 |   | eqid 2196 | 
. . . . . 6
⊢ (𝑎 ∈
(ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀))) = (𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀))) | 
| 23 | 21, 22 | fvmptg 5637 | 
. . . . 5
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ if(𝑘 ≤ 𝑁, (𝐺‘(𝐹‘𝑘)), (𝐺‘𝑀)) ∈ 𝑆) → ((𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)))‘𝑘) = if(𝑘 ≤ 𝑁, (𝐺‘(𝐹‘𝑘)), (𝐺‘𝑀))) | 
| 24 | 5, 18, 23 | syl2an2 594 | 
. . . 4
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → ((𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)))‘𝑘) = if(𝑘 ≤ 𝑁, (𝐺‘(𝐹‘𝑘)), (𝐺‘𝑀))) | 
| 25 |   | iseqf1o.8 | 
. . . 4
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → (𝐻‘𝑘) = (𝐺‘(𝐹‘𝑘))) | 
| 26 | 4, 24, 25 | 3eqtr4rd 2240 | 
. . 3
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...𝑁)) → (𝐻‘𝑘) = ((𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)))‘𝑘)) | 
| 27 |   | iseqf1o.h | 
. . 3
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → (𝐻‘𝑥) ∈ 𝑆) | 
| 28 |   | simpr 110 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑥 ∈ (ℤ≥‘𝑀)) | 
| 29 |   | fveq2 5558 | 
. . . . . . . 8
⊢ (𝑏 = (𝐹‘𝑥) → (𝐺‘𝑏) = (𝐺‘(𝐹‘𝑥))) | 
| 30 | 29 | eleq1d 2265 | 
. . . . . . 7
⊢ (𝑏 = (𝐹‘𝑥) → ((𝐺‘𝑏) ∈ 𝑆 ↔ (𝐺‘(𝐹‘𝑥)) ∈ 𝑆)) | 
| 31 |   | fveq2 5558 | 
. . . . . . . . . . 11
⊢ (𝑥 = 𝑏 → (𝐺‘𝑥) = (𝐺‘𝑏)) | 
| 32 | 31 | eleq1d 2265 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑏 → ((𝐺‘𝑥) ∈ 𝑆 ↔ (𝐺‘𝑏) ∈ 𝑆)) | 
| 33 | 32 | cbvralv 2729 | 
. . . . . . . . 9
⊢
(∀𝑥 ∈
(ℤ≥‘𝑀)(𝐺‘𝑥) ∈ 𝑆 ↔ ∀𝑏 ∈ (ℤ≥‘𝑀)(𝐺‘𝑏) ∈ 𝑆) | 
| 34 | 9, 33 | sylib 122 | 
. . . . . . . 8
⊢ (𝜑 → ∀𝑏 ∈ (ℤ≥‘𝑀)(𝐺‘𝑏) ∈ 𝑆) | 
| 35 | 34 | ad2antrr 488 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → ∀𝑏 ∈ (ℤ≥‘𝑀)(𝐺‘𝑏) ∈ 𝑆) | 
| 36 | 13 | ad2antrr 488 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → 𝐹:(𝑀...𝑁)⟶(𝑀...𝑁)) | 
| 37 |   | eluzel2 9606 | 
. . . . . . . . . . . 12
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑀 ∈ ℤ) | 
| 38 | 1, 37 | syl 14 | 
. . . . . . . . . . 11
⊢ (𝜑 → 𝑀 ∈ ℤ) | 
| 39 | 38 | ad2antrr 488 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → 𝑀 ∈ ℤ) | 
| 40 |   | eluzelz 9610 | 
. . . . . . . . . . . 12
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑁 ∈ ℤ) | 
| 41 | 1, 40 | syl 14 | 
. . . . . . . . . . 11
⊢ (𝜑 → 𝑁 ∈ ℤ) | 
| 42 | 41 | ad2antrr 488 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → 𝑁 ∈ ℤ) | 
| 43 |   | eluzelz 9610 | 
. . . . . . . . . . 11
⊢ (𝑥 ∈
(ℤ≥‘𝑀) → 𝑥 ∈ ℤ) | 
| 44 | 43 | ad2antlr 489 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → 𝑥 ∈ ℤ) | 
| 45 |   | eluzle 9613 | 
. . . . . . . . . . 11
⊢ (𝑥 ∈
(ℤ≥‘𝑀) → 𝑀 ≤ 𝑥) | 
| 46 | 45 | ad2antlr 489 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → 𝑀 ≤ 𝑥) | 
| 47 |   | simpr 110 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → 𝑥 ≤ 𝑁) | 
| 48 |   | elfz4 10093 | 
. . . . . . . . . 10
⊢ (((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ ∧ 𝑥 ∈ ℤ) ∧ (𝑀 ≤ 𝑥 ∧ 𝑥 ≤ 𝑁)) → 𝑥 ∈ (𝑀...𝑁)) | 
| 49 | 39, 42, 44, 46, 47, 48 | syl32anc 1257 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → 𝑥 ∈ (𝑀...𝑁)) | 
| 50 | 36, 49 | ffvelcdmd 5698 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → (𝐹‘𝑥) ∈ (𝑀...𝑁)) | 
| 51 |   | elfzuz 10096 | 
. . . . . . . 8
⊢ ((𝐹‘𝑥) ∈ (𝑀...𝑁) → (𝐹‘𝑥) ∈ (ℤ≥‘𝑀)) | 
| 52 | 50, 51 | syl 14 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → (𝐹‘𝑥) ∈ (ℤ≥‘𝑀)) | 
| 53 | 30, 35, 52 | rspcdva 2873 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ 𝑥 ≤ 𝑁) → (𝐺‘(𝐹‘𝑥)) ∈ 𝑆) | 
| 54 |   | fveq2 5558 | 
. . . . . . . . 9
⊢ (𝑥 = 𝑀 → (𝐺‘𝑥) = (𝐺‘𝑀)) | 
| 55 | 54 | eleq1d 2265 | 
. . . . . . . 8
⊢ (𝑥 = 𝑀 → ((𝐺‘𝑥) ∈ 𝑆 ↔ (𝐺‘𝑀) ∈ 𝑆)) | 
| 56 |   | uzid 9615 | 
. . . . . . . . 9
⊢ (𝑀 ∈ ℤ → 𝑀 ∈
(ℤ≥‘𝑀)) | 
| 57 | 38, 56 | syl 14 | 
. . . . . . . 8
⊢ (𝜑 → 𝑀 ∈ (ℤ≥‘𝑀)) | 
| 58 | 55, 9, 57 | rspcdva 2873 | 
. . . . . . 7
⊢ (𝜑 → (𝐺‘𝑀) ∈ 𝑆) | 
| 59 | 58 | ad2antrr 488 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) ∧ ¬ 𝑥 ≤ 𝑁) → (𝐺‘𝑀) ∈ 𝑆) | 
| 60 | 41 | adantr 276 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → 𝑁 ∈ ℤ) | 
| 61 |   | zdcle 9402 | 
. . . . . . 7
⊢ ((𝑥 ∈ ℤ ∧ 𝑁 ∈ ℤ) →
DECID 𝑥 ≤
𝑁) | 
| 62 | 43, 60, 61 | syl2an2 594 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → DECID
𝑥 ≤ 𝑁) | 
| 63 | 53, 59, 62 | ifcldadc 3590 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀)) ∈ 𝑆) | 
| 64 |   | breq1 4036 | 
. . . . . . 7
⊢ (𝑎 = 𝑥 → (𝑎 ≤ 𝑁 ↔ 𝑥 ≤ 𝑁)) | 
| 65 |   | 2fveq3 5563 | 
. . . . . . 7
⊢ (𝑎 = 𝑥 → (𝐺‘(𝐹‘𝑎)) = (𝐺‘(𝐹‘𝑥))) | 
| 66 | 64, 65 | ifbieq1d 3583 | 
. . . . . 6
⊢ (𝑎 = 𝑥 → if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)) = if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀))) | 
| 67 | 66, 22 | fvmptg 5637 | 
. . . . 5
⊢ ((𝑥 ∈
(ℤ≥‘𝑀) ∧ if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀)) ∈ 𝑆) → ((𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)))‘𝑥) = if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀))) | 
| 68 | 28, 63, 67 | syl2anc 411 | 
. . . 4
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → ((𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)))‘𝑥) = if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀))) | 
| 69 | 68, 63 | eqeltrd 2273 | 
. . 3
⊢ ((𝜑 ∧ 𝑥 ∈ (ℤ≥‘𝑀)) → ((𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀)))‘𝑥) ∈ 𝑆) | 
| 70 |   | iseqf1o.1 | 
. . 3
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) ∈ 𝑆) | 
| 71 | 1, 26, 27, 69, 70 | seq3fveq 10571 | 
. 2
⊢ (𝜑 → (seq𝑀( + , 𝐻)‘𝑁) = (seq𝑀( + , (𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀))))‘𝑁)) | 
| 72 |   | iseqf1o.2 | 
. . 3
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆)) → (𝑥 + 𝑦) = (𝑦 + 𝑥)) | 
| 73 |   | iseqf1o.3 | 
. . 3
⊢ ((𝜑 ∧ (𝑥 ∈ 𝑆 ∧ 𝑦 ∈ 𝑆 ∧ 𝑧 ∈ 𝑆)) → ((𝑥 + 𝑦) + 𝑧) = (𝑥 + (𝑦 + 𝑧))) | 
| 74 | 66 | cbvmptv 4129 | 
. . 3
⊢ (𝑎 ∈
(ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀))) = (𝑥 ∈ (ℤ≥‘𝑀) ↦ if(𝑥 ≤ 𝑁, (𝐺‘(𝐹‘𝑥)), (𝐺‘𝑀))) | 
| 75 | 70, 72, 73, 1, 11, 8, 74 | seq3f1oleml 10608 | 
. 2
⊢ (𝜑 → (seq𝑀( + , (𝑎 ∈ (ℤ≥‘𝑀) ↦ if(𝑎 ≤ 𝑁, (𝐺‘(𝐹‘𝑎)), (𝐺‘𝑀))))‘𝑁) = (seq𝑀( + , 𝐺)‘𝑁)) | 
| 76 | 71, 75 | eqtrd 2229 | 
1
⊢ (𝜑 → (seq𝑀( + , 𝐻)‘𝑁) = (seq𝑀( + , 𝐺)‘𝑁)) |