| Step | Hyp | Ref
 | Expression | 
| 1 |   | isumsplit.1 | 
. 2
⊢ 𝑍 =
(ℤ≥‘𝑀) | 
| 2 |   | isumsplit.3 | 
. . . 4
⊢ (𝜑 → 𝑁 ∈ 𝑍) | 
| 3 | 2, 1 | eleqtrdi 2289 | 
. . 3
⊢ (𝜑 → 𝑁 ∈ (ℤ≥‘𝑀)) | 
| 4 |   | eluzel2 9606 | 
. . 3
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑀 ∈ ℤ) | 
| 5 | 3, 4 | syl 14 | 
. 2
⊢ (𝜑 → 𝑀 ∈ ℤ) | 
| 6 |   | isumsplit.4 | 
. 2
⊢ ((𝜑 ∧ 𝑘 ∈ 𝑍) → (𝐹‘𝑘) = 𝐴) | 
| 7 |   | isumsplit.5 | 
. 2
⊢ ((𝜑 ∧ 𝑘 ∈ 𝑍) → 𝐴 ∈ ℂ) | 
| 8 |   | isumsplit.2 | 
. . 3
⊢ 𝑊 =
(ℤ≥‘𝑁) | 
| 9 |   | eluzelz 9610 | 
. . . 4
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑁 ∈ ℤ) | 
| 10 | 3, 9 | syl 14 | 
. . 3
⊢ (𝜑 → 𝑁 ∈ ℤ) | 
| 11 |   | uzss 9622 | 
. . . . . . . 8
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → (ℤ≥‘𝑁) ⊆
(ℤ≥‘𝑀)) | 
| 12 | 3, 11 | syl 14 | 
. . . . . . 7
⊢ (𝜑 →
(ℤ≥‘𝑁) ⊆
(ℤ≥‘𝑀)) | 
| 13 | 12, 8, 1 | 3sstr4g 3226 | 
. . . . . 6
⊢ (𝜑 → 𝑊 ⊆ 𝑍) | 
| 14 | 13 | sselda 3183 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑘 ∈ 𝑊) → 𝑘 ∈ 𝑍) | 
| 15 | 14, 6 | syldan 282 | 
. . . 4
⊢ ((𝜑 ∧ 𝑘 ∈ 𝑊) → (𝐹‘𝑘) = 𝐴) | 
| 16 | 14, 7 | syldan 282 | 
. . . 4
⊢ ((𝜑 ∧ 𝑘 ∈ 𝑊) → 𝐴 ∈ ℂ) | 
| 17 |   | isumsplit.6 | 
. . . . 5
⊢ (𝜑 → seq𝑀( + , 𝐹) ∈ dom ⇝ ) | 
| 18 | 6, 7 | eqeltrd 2273 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑘 ∈ 𝑍) → (𝐹‘𝑘) ∈ ℂ) | 
| 19 | 1, 2, 18 | iserex 11504 | 
. . . . 5
⊢ (𝜑 → (seq𝑀( + , 𝐹) ∈ dom ⇝ ↔ seq𝑁( + , 𝐹) ∈ dom ⇝ )) | 
| 20 | 17, 19 | mpbid 147 | 
. . . 4
⊢ (𝜑 → seq𝑁( + , 𝐹) ∈ dom ⇝ ) | 
| 21 | 8, 10, 15, 16, 20 | isumclim2 11587 | 
. . 3
⊢ (𝜑 → seq𝑁( + , 𝐹) ⇝ Σ𝑘 ∈ 𝑊 𝐴) | 
| 22 |   | peano2zm 9364 | 
. . . . . 6
⊢ (𝑁 ∈ ℤ → (𝑁 − 1) ∈
ℤ) | 
| 23 | 10, 22 | syl 14 | 
. . . . 5
⊢ (𝜑 → (𝑁 − 1) ∈ ℤ) | 
| 24 | 5, 23 | fzfigd 10523 | 
. . . 4
⊢ (𝜑 → (𝑀...(𝑁 − 1)) ∈ Fin) | 
| 25 |   | elfzuz 10096 | 
. . . . . 6
⊢ (𝑘 ∈ (𝑀...(𝑁 − 1)) → 𝑘 ∈ (ℤ≥‘𝑀)) | 
| 26 | 25, 1 | eleqtrrdi 2290 | 
. . . . 5
⊢ (𝑘 ∈ (𝑀...(𝑁 − 1)) → 𝑘 ∈ 𝑍) | 
| 27 | 26, 7 | sylan2 286 | 
. . . 4
⊢ ((𝜑 ∧ 𝑘 ∈ (𝑀...(𝑁 − 1))) → 𝐴 ∈ ℂ) | 
| 28 | 24, 27 | fsumcl 11565 | 
. . 3
⊢ (𝜑 → Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 ∈ ℂ) | 
| 29 | 14, 18 | syldan 282 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑘 ∈ 𝑊) → (𝐹‘𝑘) ∈ ℂ) | 
| 30 | 8, 10, 29 | serf 10575 | 
. . . 4
⊢ (𝜑 → seq𝑁( + , 𝐹):𝑊⟶ℂ) | 
| 31 | 30 | ffvelcdmda 5697 | 
. . 3
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (seq𝑁( + , 𝐹)‘𝑗) ∈ ℂ) | 
| 32 | 5 | zred 9448 | 
. . . . . . . . . . . 12
⊢ (𝜑 → 𝑀 ∈ ℝ) | 
| 33 | 32 | ltm1d 8959 | 
. . . . . . . . . . 11
⊢ (𝜑 → (𝑀 − 1) < 𝑀) | 
| 34 |   | peano2zm 9364 | 
. . . . . . . . . . . . 13
⊢ (𝑀 ∈ ℤ → (𝑀 − 1) ∈
ℤ) | 
| 35 | 5, 34 | syl 14 | 
. . . . . . . . . . . 12
⊢ (𝜑 → (𝑀 − 1) ∈ ℤ) | 
| 36 |   | fzn 10117 | 
. . . . . . . . . . . 12
⊢ ((𝑀 ∈ ℤ ∧ (𝑀 − 1) ∈ ℤ)
→ ((𝑀 − 1) <
𝑀 ↔ (𝑀...(𝑀 − 1)) = ∅)) | 
| 37 | 5, 35, 36 | syl2anc 411 | 
. . . . . . . . . . 11
⊢ (𝜑 → ((𝑀 − 1) < 𝑀 ↔ (𝑀...(𝑀 − 1)) = ∅)) | 
| 38 | 33, 37 | mpbid 147 | 
. . . . . . . . . 10
⊢ (𝜑 → (𝑀...(𝑀 − 1)) = ∅) | 
| 39 | 38 | sumeq1d 11531 | 
. . . . . . . . 9
⊢ (𝜑 → Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴 = Σ𝑘 ∈ ∅ 𝐴) | 
| 40 | 39 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴 = Σ𝑘 ∈ ∅ 𝐴) | 
| 41 |   | sum0 11553 | 
. . . . . . . 8
⊢
Σ𝑘 ∈
∅ 𝐴 =
0 | 
| 42 | 40, 41 | eqtrdi 2245 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴 = 0) | 
| 43 | 42 | oveq1d 5937 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴 + (seq𝑀( + , 𝐹)‘𝑗)) = (0 + (seq𝑀( + , 𝐹)‘𝑗))) | 
| 44 | 13 | sselda 3183 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → 𝑗 ∈ 𝑍) | 
| 45 | 1, 5, 18 | serf 10575 | 
. . . . . . . . 9
⊢ (𝜑 → seq𝑀( + , 𝐹):𝑍⟶ℂ) | 
| 46 | 45 | ffvelcdmda 5697 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑍) → (seq𝑀( + , 𝐹)‘𝑗) ∈ ℂ) | 
| 47 | 44, 46 | syldan 282 | 
. . . . . . 7
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (seq𝑀( + , 𝐹)‘𝑗) ∈ ℂ) | 
| 48 | 47 | addlidd 8176 | 
. . . . . 6
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (0 + (seq𝑀( + , 𝐹)‘𝑗)) = (seq𝑀( + , 𝐹)‘𝑗)) | 
| 49 | 43, 48 | eqtr2d 2230 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (seq𝑀( + , 𝐹)‘𝑗) = (Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴 + (seq𝑀( + , 𝐹)‘𝑗))) | 
| 50 |   | oveq1 5929 | 
. . . . . . . . 9
⊢ (𝑁 = 𝑀 → (𝑁 − 1) = (𝑀 − 1)) | 
| 51 | 50 | oveq2d 5938 | 
. . . . . . . 8
⊢ (𝑁 = 𝑀 → (𝑀...(𝑁 − 1)) = (𝑀...(𝑀 − 1))) | 
| 52 | 51 | sumeq1d 11531 | 
. . . . . . 7
⊢ (𝑁 = 𝑀 → Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 = Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴) | 
| 53 |   | seqeq1 10542 | 
. . . . . . . 8
⊢ (𝑁 = 𝑀 → seq𝑁( + , 𝐹) = seq𝑀( + , 𝐹)) | 
| 54 | 53 | fveq1d 5560 | 
. . . . . . 7
⊢ (𝑁 = 𝑀 → (seq𝑁( + , 𝐹)‘𝑗) = (seq𝑀( + , 𝐹)‘𝑗)) | 
| 55 | 52, 54 | oveq12d 5940 | 
. . . . . 6
⊢ (𝑁 = 𝑀 → (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + (seq𝑁( + , 𝐹)‘𝑗)) = (Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴 + (seq𝑀( + , 𝐹)‘𝑗))) | 
| 56 | 55 | eqeq2d 2208 | 
. . . . 5
⊢ (𝑁 = 𝑀 → ((seq𝑀( + , 𝐹)‘𝑗) = (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + (seq𝑁( + , 𝐹)‘𝑗)) ↔ (seq𝑀( + , 𝐹)‘𝑗) = (Σ𝑘 ∈ (𝑀...(𝑀 − 1))𝐴 + (seq𝑀( + , 𝐹)‘𝑗)))) | 
| 57 | 49, 56 | syl5ibrcom 157 | 
. . . 4
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (𝑁 = 𝑀 → (seq𝑀( + , 𝐹)‘𝑗) = (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + (seq𝑁( + , 𝐹)‘𝑗)))) | 
| 58 |   | addcl 8004 | 
. . . . . . . 8
⊢ ((𝑘 ∈ ℂ ∧ 𝑚 ∈ ℂ) → (𝑘 + 𝑚) ∈ ℂ) | 
| 59 | 58 | adantl 277 | 
. . . . . . 7
⊢ ((((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) ∧ (𝑘 ∈ ℂ ∧ 𝑚 ∈ ℂ)) → (𝑘 + 𝑚) ∈ ℂ) | 
| 60 |   | addass 8009 | 
. . . . . . . 8
⊢ ((𝑘 ∈ ℂ ∧ 𝑚 ∈ ℂ ∧ 𝑥 ∈ ℂ) → ((𝑘 + 𝑚) + 𝑥) = (𝑘 + (𝑚 + 𝑥))) | 
| 61 | 60 | adantl 277 | 
. . . . . . 7
⊢ ((((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) ∧ (𝑘 ∈ ℂ ∧ 𝑚 ∈ ℂ ∧ 𝑥 ∈ ℂ)) → ((𝑘 + 𝑚) + 𝑥) = (𝑘 + (𝑚 + 𝑥))) | 
| 62 |   | simplr 528 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → 𝑗 ∈ 𝑊) | 
| 63 |   | simpll 527 | 
. . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → 𝜑) | 
| 64 | 10 | zcnd 9449 | 
. . . . . . . . . . . . 13
⊢ (𝜑 → 𝑁 ∈ ℂ) | 
| 65 |   | ax-1cn 7972 | 
. . . . . . . . . . . . 13
⊢ 1 ∈
ℂ | 
| 66 |   | npcan 8235 | 
. . . . . . . . . . . . 13
⊢ ((𝑁 ∈ ℂ ∧ 1 ∈
ℂ) → ((𝑁 −
1) + 1) = 𝑁) | 
| 67 | 64, 65, 66 | sylancl 413 | 
. . . . . . . . . . . 12
⊢ (𝜑 → ((𝑁 − 1) + 1) = 𝑁) | 
| 68 | 67 | eqcomd 2202 | 
. . . . . . . . . . 11
⊢ (𝜑 → 𝑁 = ((𝑁 − 1) + 1)) | 
| 69 | 63, 68 | syl 14 | 
. . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → 𝑁 = ((𝑁 − 1) + 1)) | 
| 70 | 69 | fveq2d 5562 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) →
(ℤ≥‘𝑁) = (ℤ≥‘((𝑁 − 1) +
1))) | 
| 71 | 8, 70 | eqtrid 2241 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → 𝑊 = (ℤ≥‘((𝑁 − 1) +
1))) | 
| 72 | 62, 71 | eleqtrd 2275 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → 𝑗 ∈
(ℤ≥‘((𝑁 − 1) + 1))) | 
| 73 | 5 | adantr 276 | 
. . . . . . . 8
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → 𝑀 ∈ ℤ) | 
| 74 |   | eluzp1m1 9625 | 
. . . . . . . 8
⊢ ((𝑀 ∈ ℤ ∧ 𝑁 ∈
(ℤ≥‘(𝑀 + 1))) → (𝑁 − 1) ∈
(ℤ≥‘𝑀)) | 
| 75 | 73, 74 | sylan 283 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → (𝑁 − 1) ∈
(ℤ≥‘𝑀)) | 
| 76 | 1 | eleq2i 2263 | 
. . . . . . . . . 10
⊢ (𝑘 ∈ 𝑍 ↔ 𝑘 ∈ (ℤ≥‘𝑀)) | 
| 77 | 76, 6 | sylan2br 288 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑘 ∈ (ℤ≥‘𝑀)) → (𝐹‘𝑘) = 𝐴) | 
| 78 | 63, 77 | sylan 283 | 
. . . . . . . 8
⊢ ((((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) ∧ 𝑘 ∈ (ℤ≥‘𝑀)) → (𝐹‘𝑘) = 𝐴) | 
| 79 | 76, 7 | sylan2br 288 | 
. . . . . . . . 9
⊢ ((𝜑 ∧ 𝑘 ∈ (ℤ≥‘𝑀)) → 𝐴 ∈ ℂ) | 
| 80 | 63, 79 | sylan 283 | 
. . . . . . . 8
⊢ ((((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) ∧ 𝑘 ∈ (ℤ≥‘𝑀)) → 𝐴 ∈ ℂ) | 
| 81 | 78, 80 | eqeltrd 2273 | 
. . . . . . 7
⊢ ((((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) ∧ 𝑘 ∈ (ℤ≥‘𝑀)) → (𝐹‘𝑘) ∈ ℂ) | 
| 82 | 59, 61, 72, 75, 81 | seq3split 10580 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → (seq𝑀( + , 𝐹)‘𝑗) = ((seq𝑀( + , 𝐹)‘(𝑁 − 1)) + (seq((𝑁 − 1) + 1)( + , 𝐹)‘𝑗))) | 
| 83 | 78, 75, 80 | fsum3ser 11562 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 = (seq𝑀( + , 𝐹)‘(𝑁 − 1))) | 
| 84 | 69 | seqeq1d 10545 | 
. . . . . . . 8
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → seq𝑁( + , 𝐹) = seq((𝑁 − 1) + 1)( + , 𝐹)) | 
| 85 | 84 | fveq1d 5560 | 
. . . . . . 7
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → (seq𝑁( + , 𝐹)‘𝑗) = (seq((𝑁 − 1) + 1)( + , 𝐹)‘𝑗)) | 
| 86 | 83, 85 | oveq12d 5940 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + (seq𝑁( + , 𝐹)‘𝑗)) = ((seq𝑀( + , 𝐹)‘(𝑁 − 1)) + (seq((𝑁 − 1) + 1)( + , 𝐹)‘𝑗))) | 
| 87 | 82, 86 | eqtr4d 2232 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑗 ∈ 𝑊) ∧ 𝑁 ∈ (ℤ≥‘(𝑀 + 1))) → (seq𝑀( + , 𝐹)‘𝑗) = (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + (seq𝑁( + , 𝐹)‘𝑗))) | 
| 88 | 87 | ex 115 | 
. . . 4
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (𝑁 ∈ (ℤ≥‘(𝑀 + 1)) → (seq𝑀( + , 𝐹)‘𝑗) = (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + (seq𝑁( + , 𝐹)‘𝑗)))) | 
| 89 |   | uzp1 9635 | 
. . . . . 6
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → (𝑁 = 𝑀 ∨ 𝑁 ∈ (ℤ≥‘(𝑀 + 1)))) | 
| 90 | 3, 89 | syl 14 | 
. . . . 5
⊢ (𝜑 → (𝑁 = 𝑀 ∨ 𝑁 ∈ (ℤ≥‘(𝑀 + 1)))) | 
| 91 | 90 | adantr 276 | 
. . . 4
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (𝑁 = 𝑀 ∨ 𝑁 ∈ (ℤ≥‘(𝑀 + 1)))) | 
| 92 | 57, 88, 91 | mpjaod 719 | 
. . 3
⊢ ((𝜑 ∧ 𝑗 ∈ 𝑊) → (seq𝑀( + , 𝐹)‘𝑗) = (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + (seq𝑁( + , 𝐹)‘𝑗))) | 
| 93 | 8, 10, 21, 28, 17, 31, 92 | climaddc2 11495 | 
. 2
⊢ (𝜑 → seq𝑀( + , 𝐹) ⇝ (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + Σ𝑘 ∈ 𝑊 𝐴)) | 
| 94 | 1, 5, 6, 7, 93 | isumclim 11586 | 
1
⊢ (𝜑 → Σ𝑘 ∈ 𝑍 𝐴 = (Σ𝑘 ∈ (𝑀...(𝑁 − 1))𝐴 + Σ𝑘 ∈ 𝑊 𝐴)) |