| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | fprodntriv.2 | . . . . 5
⊢ (𝜑 → 𝑁 ∈ 𝑍) | 
| 2 |  | fprodntriv.1 | . . . . 5
⊢ 𝑍 =
(ℤ≥‘𝑀) | 
| 3 | 1, 2 | eleqtrdi 2850 | . . . 4
⊢ (𝜑 → 𝑁 ∈ (ℤ≥‘𝑀)) | 
| 4 |  | peano2uz 12944 | . . . 4
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → (𝑁 + 1) ∈
(ℤ≥‘𝑀)) | 
| 5 | 3, 4 | syl 17 | . . 3
⊢ (𝜑 → (𝑁 + 1) ∈
(ℤ≥‘𝑀)) | 
| 6 | 5, 2 | eleqtrrdi 2851 | . 2
⊢ (𝜑 → (𝑁 + 1) ∈ 𝑍) | 
| 7 |  | ax-1ne0 11225 | . . 3
⊢ 1 ≠
0 | 
| 8 |  | eqid 2736 | . . . 4
⊢
(ℤ≥‘(𝑁 + 1)) =
(ℤ≥‘(𝑁 + 1)) | 
| 9 |  | eluzelz 12889 | . . . . . . 7
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑁 ∈ ℤ) | 
| 10 | 9, 2 | eleq2s 2858 | . . . . . 6
⊢ (𝑁 ∈ 𝑍 → 𝑁 ∈ ℤ) | 
| 11 | 1, 10 | syl 17 | . . . . 5
⊢ (𝜑 → 𝑁 ∈ ℤ) | 
| 12 | 11 | peano2zd 12727 | . . . 4
⊢ (𝜑 → (𝑁 + 1) ∈ ℤ) | 
| 13 |  | seqex 14045 | . . . . 5
⊢ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ∈ V | 
| 14 | 13 | a1i 11 | . . . 4
⊢ (𝜑 → seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ∈ V) | 
| 15 |  | 1cnd 11257 | . . . 4
⊢ (𝜑 → 1 ∈
ℂ) | 
| 16 |  | simpr 484 | . . . . . 6
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) → 𝑛 ∈
(ℤ≥‘(𝑁 + 1))) | 
| 17 |  | fprodntriv.3 | . . . . . . . . . 10
⊢ (𝜑 → 𝐴 ⊆ (𝑀...𝑁)) | 
| 18 | 17 | ad2antrr 726 | . . . . . . . . 9
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝐴 ⊆ (𝑀...𝑁)) | 
| 19 | 11 | ad2antrr 726 | . . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑁 ∈ ℤ) | 
| 20 | 19 | zred 12724 | . . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑁 ∈ ℝ) | 
| 21 | 19 | peano2zd 12727 | . . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → (𝑁 + 1) ∈ ℤ) | 
| 22 | 21 | zred 12724 | . . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → (𝑁 + 1) ∈ ℝ) | 
| 23 |  | elfzelz 13565 | . . . . . . . . . . . . . . . 16
⊢ (𝑚 ∈ ((𝑁 + 1)...𝑛) → 𝑚 ∈ ℤ) | 
| 24 | 23 | adantl 481 | . . . . . . . . . . . . . . 15
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑚 ∈ ℤ) | 
| 25 | 24 | zred 12724 | . . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑚 ∈ ℝ) | 
| 26 | 20 | ltp1d 12199 | . . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑁 < (𝑁 + 1)) | 
| 27 |  | elfzle1 13568 | . . . . . . . . . . . . . . 15
⊢ (𝑚 ∈ ((𝑁 + 1)...𝑛) → (𝑁 + 1) ≤ 𝑚) | 
| 28 | 27 | adantl 481 | . . . . . . . . . . . . . 14
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → (𝑁 + 1) ≤ 𝑚) | 
| 29 | 20, 22, 25, 26, 28 | ltletrd 11422 | . . . . . . . . . . . . 13
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑁 < 𝑚) | 
| 30 | 20, 25 | ltnled 11409 | . . . . . . . . . . . . 13
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → (𝑁 < 𝑚 ↔ ¬ 𝑚 ≤ 𝑁)) | 
| 31 | 29, 30 | mpbid 232 | . . . . . . . . . . . 12
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → ¬ 𝑚 ≤ 𝑁) | 
| 32 | 31 | intnand 488 | . . . . . . . . . . 11
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → ¬ (𝑀 ≤ 𝑚 ∧ 𝑚 ≤ 𝑁)) | 
| 33 | 32 | intnand 488 | . . . . . . . . . 10
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → ¬ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ ∧ 𝑚 ∈ ℤ) ∧ (𝑀 ≤ 𝑚 ∧ 𝑚 ≤ 𝑁))) | 
| 34 |  | elfz2 13555 | . . . . . . . . . 10
⊢ (𝑚 ∈ (𝑀...𝑁) ↔ ((𝑀 ∈ ℤ ∧ 𝑁 ∈ ℤ ∧ 𝑚 ∈ ℤ) ∧ (𝑀 ≤ 𝑚 ∧ 𝑚 ≤ 𝑁))) | 
| 35 | 33, 34 | sylnibr 329 | . . . . . . . . 9
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → ¬ 𝑚 ∈ (𝑀...𝑁)) | 
| 36 | 18, 35 | ssneldd 3985 | . . . . . . . 8
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → ¬ 𝑚 ∈ 𝐴) | 
| 37 | 36 | iffalsed 4535 | . . . . . . 7
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → if(𝑚 ∈ 𝐴, ⦋𝑚 / 𝑘⦌𝐵, 1) = 1) | 
| 38 |  | fzssuz 13606 | . . . . . . . . . 10
⊢ ((𝑁 + 1)...𝑛) ⊆
(ℤ≥‘(𝑁 + 1)) | 
| 39 | 5 | adantr 480 | . . . . . . . . . . . 12
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) → (𝑁 + 1) ∈
(ℤ≥‘𝑀)) | 
| 40 |  | uzss 12902 | . . . . . . . . . . . 12
⊢ ((𝑁 + 1) ∈
(ℤ≥‘𝑀) →
(ℤ≥‘(𝑁 + 1)) ⊆
(ℤ≥‘𝑀)) | 
| 41 | 39, 40 | syl 17 | . . . . . . . . . . 11
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) →
(ℤ≥‘(𝑁 + 1)) ⊆
(ℤ≥‘𝑀)) | 
| 42 | 41, 2 | sseqtrrdi 4024 | . . . . . . . . . 10
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) →
(ℤ≥‘(𝑁 + 1)) ⊆ 𝑍) | 
| 43 | 38, 42 | sstrid 3994 | . . . . . . . . 9
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) → ((𝑁 + 1)...𝑛) ⊆ 𝑍) | 
| 44 | 43 | sselda 3982 | . . . . . . . 8
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑚 ∈ 𝑍) | 
| 45 |  | ax-1cn 11214 | . . . . . . . . 9
⊢ 1 ∈
ℂ | 
| 46 | 37, 45 | eqeltrdi 2848 | . . . . . . . 8
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → if(𝑚 ∈ 𝐴, ⦋𝑚 / 𝑘⦌𝐵, 1) ∈ ℂ) | 
| 47 |  | nfcv 2904 | . . . . . . . . 9
⊢
Ⅎ𝑘𝑚 | 
| 48 |  | nfv 1913 | . . . . . . . . . 10
⊢
Ⅎ𝑘 𝑚 ∈ 𝐴 | 
| 49 |  | nfcsb1v 3922 | . . . . . . . . . 10
⊢
Ⅎ𝑘⦋𝑚 / 𝑘⦌𝐵 | 
| 50 |  | nfcv 2904 | . . . . . . . . . 10
⊢
Ⅎ𝑘1 | 
| 51 | 48, 49, 50 | nfif 4555 | . . . . . . . . 9
⊢
Ⅎ𝑘if(𝑚 ∈ 𝐴, ⦋𝑚 / 𝑘⦌𝐵, 1) | 
| 52 |  | eleq1w 2823 | . . . . . . . . . 10
⊢ (𝑘 = 𝑚 → (𝑘 ∈ 𝐴 ↔ 𝑚 ∈ 𝐴)) | 
| 53 |  | csbeq1a 3912 | . . . . . . . . . 10
⊢ (𝑘 = 𝑚 → 𝐵 = ⦋𝑚 / 𝑘⦌𝐵) | 
| 54 | 52, 53 | ifbieq1d 4549 | . . . . . . . . 9
⊢ (𝑘 = 𝑚 → if(𝑘 ∈ 𝐴, 𝐵, 1) = if(𝑚 ∈ 𝐴, ⦋𝑚 / 𝑘⦌𝐵, 1)) | 
| 55 |  | eqid 2736 | . . . . . . . . 9
⊢ (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1)) = (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1)) | 
| 56 | 47, 51, 54, 55 | fvmptf 7036 | . . . . . . . 8
⊢ ((𝑚 ∈ 𝑍 ∧ if(𝑚 ∈ 𝐴, ⦋𝑚 / 𝑘⦌𝐵, 1) ∈ ℂ) → ((𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))‘𝑚) = if(𝑚 ∈ 𝐴, ⦋𝑚 / 𝑘⦌𝐵, 1)) | 
| 57 | 44, 46, 56 | syl2anc 584 | . . . . . . 7
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → ((𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))‘𝑚) = if(𝑚 ∈ 𝐴, ⦋𝑚 / 𝑘⦌𝐵, 1)) | 
| 58 |  | elfzuz 13561 | . . . . . . . . 9
⊢ (𝑚 ∈ ((𝑁 + 1)...𝑛) → 𝑚 ∈ (ℤ≥‘(𝑁 + 1))) | 
| 59 | 58 | adantl 481 | . . . . . . . 8
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → 𝑚 ∈ (ℤ≥‘(𝑁 + 1))) | 
| 60 |  | 1ex 11258 | . . . . . . . . 9
⊢ 1 ∈
V | 
| 61 | 60 | fvconst2 7225 | . . . . . . . 8
⊢ (𝑚 ∈
(ℤ≥‘(𝑁 + 1)) →
(((ℤ≥‘(𝑁 + 1)) × {1})‘𝑚) = 1) | 
| 62 | 59, 61 | syl 17 | . . . . . . 7
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) →
(((ℤ≥‘(𝑁 + 1)) × {1})‘𝑚) = 1) | 
| 63 | 37, 57, 62 | 3eqtr4d 2786 | . . . . . 6
⊢ (((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) ∧ 𝑚 ∈ ((𝑁 + 1)...𝑛)) → ((𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))‘𝑚) = (((ℤ≥‘(𝑁 + 1)) × {1})‘𝑚)) | 
| 64 | 16, 63 | seqfveq 14068 | . . . . 5
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) → (seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1)))‘𝑛) = (seq(𝑁 + 1)( · ,
((ℤ≥‘(𝑁 + 1)) × {1}))‘𝑛)) | 
| 65 | 8 | prodf1 15928 | . . . . . 6
⊢ (𝑛 ∈
(ℤ≥‘(𝑁 + 1)) → (seq(𝑁 + 1)( · ,
((ℤ≥‘(𝑁 + 1)) × {1}))‘𝑛) = 1) | 
| 66 | 65 | adantl 481 | . . . . 5
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) → (seq(𝑁 + 1)( · ,
((ℤ≥‘(𝑁 + 1)) × {1}))‘𝑛) = 1) | 
| 67 | 64, 66 | eqtrd 2776 | . . . 4
⊢ ((𝜑 ∧ 𝑛 ∈ (ℤ≥‘(𝑁 + 1))) → (seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1)))‘𝑛) = 1) | 
| 68 | 8, 12, 14, 15, 67 | climconst 15580 | . . 3
⊢ (𝜑 → seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 1) | 
| 69 |  | neeq1 3002 | . . . . 5
⊢ (𝑦 = 1 → (𝑦 ≠ 0 ↔ 1 ≠ 0)) | 
| 70 |  | breq2 5146 | . . . . 5
⊢ (𝑦 = 1 → (seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦 ↔ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 1)) | 
| 71 | 69, 70 | anbi12d 632 | . . . 4
⊢ (𝑦 = 1 → ((𝑦 ≠ 0 ∧ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦) ↔ (1 ≠ 0 ∧ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 1))) | 
| 72 | 60, 71 | spcev 3605 | . . 3
⊢ ((1 ≠
0 ∧ seq(𝑁 + 1)(
· , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 1) → ∃𝑦(𝑦 ≠ 0 ∧ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦)) | 
| 73 | 7, 68, 72 | sylancr 587 | . 2
⊢ (𝜑 → ∃𝑦(𝑦 ≠ 0 ∧ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦)) | 
| 74 |  | seqeq1 14046 | . . . . . 6
⊢ (𝑛 = (𝑁 + 1) → seq𝑛( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) = seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1)))) | 
| 75 | 74 | breq1d 5152 | . . . . 5
⊢ (𝑛 = (𝑁 + 1) → (seq𝑛( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦 ↔ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦)) | 
| 76 | 75 | anbi2d 630 | . . . 4
⊢ (𝑛 = (𝑁 + 1) → ((𝑦 ≠ 0 ∧ seq𝑛( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦) ↔ (𝑦 ≠ 0 ∧ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦))) | 
| 77 | 76 | exbidv 1920 | . . 3
⊢ (𝑛 = (𝑁 + 1) → (∃𝑦(𝑦 ≠ 0 ∧ seq𝑛( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦) ↔ ∃𝑦(𝑦 ≠ 0 ∧ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦))) | 
| 78 | 77 | rspcev 3621 | . 2
⊢ (((𝑁 + 1) ∈ 𝑍 ∧ ∃𝑦(𝑦 ≠ 0 ∧ seq(𝑁 + 1)( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦)) → ∃𝑛 ∈ 𝑍 ∃𝑦(𝑦 ≠ 0 ∧ seq𝑛( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦)) | 
| 79 | 6, 73, 78 | syl2anc 584 | 1
⊢ (𝜑 → ∃𝑛 ∈ 𝑍 ∃𝑦(𝑦 ≠ 0 ∧ seq𝑛( · , (𝑘 ∈ 𝑍 ↦ if(𝑘 ∈ 𝐴, 𝐵, 1))) ⇝ 𝑦)) |