| Step | Hyp | Ref
 | Expression | 
| 1 |   | uzsinds.2 | 
. 2
⊢ (𝑥 = 𝑁 → (𝜑 ↔ 𝜒)) | 
| 2 |   | oveq2 5930 | 
. . . 4
⊢ (𝑤 = 𝑀 → (𝑀...𝑤) = (𝑀...𝑀)) | 
| 3 | 2 | raleqdv 2699 | 
. . 3
⊢ (𝑤 = 𝑀 → (∀𝑥 ∈ (𝑀...𝑤)𝜑 ↔ ∀𝑥 ∈ (𝑀...𝑀)𝜑)) | 
| 4 |   | oveq2 5930 | 
. . . 4
⊢ (𝑤 = 𝑘 → (𝑀...𝑤) = (𝑀...𝑘)) | 
| 5 | 4 | raleqdv 2699 | 
. . 3
⊢ (𝑤 = 𝑘 → (∀𝑥 ∈ (𝑀...𝑤)𝜑 ↔ ∀𝑥 ∈ (𝑀...𝑘)𝜑)) | 
| 6 |   | oveq2 5930 | 
. . . 4
⊢ (𝑤 = (𝑘 + 1) → (𝑀...𝑤) = (𝑀...(𝑘 + 1))) | 
| 7 | 6 | raleqdv 2699 | 
. . 3
⊢ (𝑤 = (𝑘 + 1) → (∀𝑥 ∈ (𝑀...𝑤)𝜑 ↔ ∀𝑥 ∈ (𝑀...(𝑘 + 1))𝜑)) | 
| 8 |   | oveq2 5930 | 
. . . 4
⊢ (𝑤 = 𝑁 → (𝑀...𝑤) = (𝑀...𝑁)) | 
| 9 | 8 | raleqdv 2699 | 
. . 3
⊢ (𝑤 = 𝑁 → (∀𝑥 ∈ (𝑀...𝑤)𝜑 ↔ ∀𝑥 ∈ (𝑀...𝑁)𝜑)) | 
| 10 |   | ral0 3552 | 
. . . . . . 7
⊢
∀𝑦 ∈
∅ 𝜓 | 
| 11 |   | zre 9330 | 
. . . . . . . . . 10
⊢ (𝑀 ∈ ℤ → 𝑀 ∈
ℝ) | 
| 12 | 11 | ltm1d 8959 | 
. . . . . . . . 9
⊢ (𝑀 ∈ ℤ → (𝑀 − 1) < 𝑀) | 
| 13 |   | peano2zm 9364 | 
. . . . . . . . . 10
⊢ (𝑀 ∈ ℤ → (𝑀 − 1) ∈
ℤ) | 
| 14 |   | fzn 10117 | 
. . . . . . . . . 10
⊢ ((𝑀 ∈ ℤ ∧ (𝑀 − 1) ∈ ℤ)
→ ((𝑀 − 1) <
𝑀 ↔ (𝑀...(𝑀 − 1)) = ∅)) | 
| 15 | 13, 14 | mpdan 421 | 
. . . . . . . . 9
⊢ (𝑀 ∈ ℤ → ((𝑀 − 1) < 𝑀 ↔ (𝑀...(𝑀 − 1)) = ∅)) | 
| 16 | 12, 15 | mpbid 147 | 
. . . . . . . 8
⊢ (𝑀 ∈ ℤ → (𝑀...(𝑀 − 1)) = ∅) | 
| 17 | 16 | raleqdv 2699 | 
. . . . . . 7
⊢ (𝑀 ∈ ℤ →
(∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓 ↔ ∀𝑦 ∈ ∅ 𝜓)) | 
| 18 | 10, 17 | mpbiri 168 | 
. . . . . 6
⊢ (𝑀 ∈ ℤ →
∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓) | 
| 19 |   | uzid 9615 | 
. . . . . . 7
⊢ (𝑀 ∈ ℤ → 𝑀 ∈
(ℤ≥‘𝑀)) | 
| 20 |   | uzsinds.3 | 
. . . . . . . 8
⊢ (𝑥 ∈
(ℤ≥‘𝑀) → (∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 → 𝜑)) | 
| 21 | 20 | rgen 2550 | 
. . . . . . 7
⊢
∀𝑥 ∈
(ℤ≥‘𝑀)(∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 → 𝜑) | 
| 22 |   | nfv 1542 | 
. . . . . . . . 9
⊢
Ⅎ𝑥∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓 | 
| 23 |   | nfsbc1v 3008 | 
. . . . . . . . 9
⊢
Ⅎ𝑥[𝑀 / 𝑥]𝜑 | 
| 24 | 22, 23 | nfim 1586 | 
. . . . . . . 8
⊢
Ⅎ𝑥(∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓 → [𝑀 / 𝑥]𝜑) | 
| 25 |   | oveq1 5929 | 
. . . . . . . . . . 11
⊢ (𝑥 = 𝑀 → (𝑥 − 1) = (𝑀 − 1)) | 
| 26 | 25 | oveq2d 5938 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑀 → (𝑀...(𝑥 − 1)) = (𝑀...(𝑀 − 1))) | 
| 27 | 26 | raleqdv 2699 | 
. . . . . . . . 9
⊢ (𝑥 = 𝑀 → (∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 ↔ ∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓)) | 
| 28 |   | sbceq1a 2999 | 
. . . . . . . . 9
⊢ (𝑥 = 𝑀 → (𝜑 ↔ [𝑀 / 𝑥]𝜑)) | 
| 29 | 27, 28 | imbi12d 234 | 
. . . . . . . 8
⊢ (𝑥 = 𝑀 → ((∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 → 𝜑) ↔ (∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓 → [𝑀 / 𝑥]𝜑))) | 
| 30 | 24, 29 | rspc 2862 | 
. . . . . . 7
⊢ (𝑀 ∈
(ℤ≥‘𝑀) → (∀𝑥 ∈ (ℤ≥‘𝑀)(∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 → 𝜑) → (∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓 → [𝑀 / 𝑥]𝜑))) | 
| 31 | 19, 21, 30 | mpisyl 1457 | 
. . . . . 6
⊢ (𝑀 ∈ ℤ →
(∀𝑦 ∈ (𝑀...(𝑀 − 1))𝜓 → [𝑀 / 𝑥]𝜑)) | 
| 32 | 18, 31 | mpd 13 | 
. . . . 5
⊢ (𝑀 ∈ ℤ →
[𝑀 / 𝑥]𝜑) | 
| 33 |   | ralsns 3660 | 
. . . . 5
⊢ (𝑀 ∈ ℤ →
(∀𝑥 ∈ {𝑀}𝜑 ↔ [𝑀 / 𝑥]𝜑)) | 
| 34 | 32, 33 | mpbird 167 | 
. . . 4
⊢ (𝑀 ∈ ℤ →
∀𝑥 ∈ {𝑀}𝜑) | 
| 35 |   | fzsn 10141 | 
. . . . 5
⊢ (𝑀 ∈ ℤ → (𝑀...𝑀) = {𝑀}) | 
| 36 | 35 | raleqdv 2699 | 
. . . 4
⊢ (𝑀 ∈ ℤ →
(∀𝑥 ∈ (𝑀...𝑀)𝜑 ↔ ∀𝑥 ∈ {𝑀}𝜑)) | 
| 37 | 34, 36 | mpbird 167 | 
. . 3
⊢ (𝑀 ∈ ℤ →
∀𝑥 ∈ (𝑀...𝑀)𝜑) | 
| 38 |   | simpr 110 | 
. . . . . 6
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → ∀𝑥 ∈ (𝑀...𝑘)𝜑) | 
| 39 |   | uzsinds.1 | 
. . . . . . . . . 10
⊢ (𝑥 = 𝑦 → (𝜑 ↔ 𝜓)) | 
| 40 | 39 | cbvralv 2729 | 
. . . . . . . . 9
⊢
(∀𝑥 ∈
(𝑀...𝑘)𝜑 ↔ ∀𝑦 ∈ (𝑀...𝑘)𝜓) | 
| 41 | 38, 40 | sylib 122 | 
. . . . . . . 8
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → ∀𝑦 ∈ (𝑀...𝑘)𝜓) | 
| 42 |   | eluzelz 9610 | 
. . . . . . . . . . . . . 14
⊢ (𝑘 ∈
(ℤ≥‘𝑀) → 𝑘 ∈ ℤ) | 
| 43 | 42 | adantr 276 | 
. . . . . . . . . . . . 13
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → 𝑘 ∈ ℤ) | 
| 44 | 43 | zcnd 9449 | 
. . . . . . . . . . . 12
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → 𝑘 ∈ ℂ) | 
| 45 |   | 1cnd 8042 | 
. . . . . . . . . . . 12
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → 1 ∈ ℂ) | 
| 46 | 44, 45 | pncand 8338 | 
. . . . . . . . . . 11
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → ((𝑘 + 1) − 1) = 𝑘) | 
| 47 | 46 | oveq2d 5938 | 
. . . . . . . . . 10
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (𝑀...((𝑘 + 1) − 1)) = (𝑀...𝑘)) | 
| 48 | 47 | raleqdv 2699 | 
. . . . . . . . 9
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (∀𝑦 ∈ (𝑀...((𝑘 + 1) − 1))𝜓 ↔ ∀𝑦 ∈ (𝑀...𝑘)𝜓)) | 
| 49 |   | peano2uz 9657 | 
. . . . . . . . . . 11
⊢ (𝑘 ∈
(ℤ≥‘𝑀) → (𝑘 + 1) ∈
(ℤ≥‘𝑀)) | 
| 50 | 49 | adantr 276 | 
. . . . . . . . . 10
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (𝑘 + 1) ∈
(ℤ≥‘𝑀)) | 
| 51 |   | nfv 1542 | 
. . . . . . . . . . . 12
⊢
Ⅎ𝑥∀𝑦 ∈ (𝑀...((𝑘 + 1) − 1))𝜓 | 
| 52 |   | nfsbc1v 3008 | 
. . . . . . . . . . . 12
⊢
Ⅎ𝑥[(𝑘 + 1) / 𝑥]𝜑 | 
| 53 | 51, 52 | nfim 1586 | 
. . . . . . . . . . 11
⊢
Ⅎ𝑥(∀𝑦 ∈ (𝑀...((𝑘 + 1) − 1))𝜓 → [(𝑘 + 1) / 𝑥]𝜑) | 
| 54 |   | oveq1 5929 | 
. . . . . . . . . . . . . 14
⊢ (𝑥 = (𝑘 + 1) → (𝑥 − 1) = ((𝑘 + 1) − 1)) | 
| 55 | 54 | oveq2d 5938 | 
. . . . . . . . . . . . 13
⊢ (𝑥 = (𝑘 + 1) → (𝑀...(𝑥 − 1)) = (𝑀...((𝑘 + 1) − 1))) | 
| 56 | 55 | raleqdv 2699 | 
. . . . . . . . . . . 12
⊢ (𝑥 = (𝑘 + 1) → (∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 ↔ ∀𝑦 ∈ (𝑀...((𝑘 + 1) − 1))𝜓)) | 
| 57 |   | sbceq1a 2999 | 
. . . . . . . . . . . 12
⊢ (𝑥 = (𝑘 + 1) → (𝜑 ↔ [(𝑘 + 1) / 𝑥]𝜑)) | 
| 58 | 56, 57 | imbi12d 234 | 
. . . . . . . . . . 11
⊢ (𝑥 = (𝑘 + 1) → ((∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 → 𝜑) ↔ (∀𝑦 ∈ (𝑀...((𝑘 + 1) − 1))𝜓 → [(𝑘 + 1) / 𝑥]𝜑))) | 
| 59 | 53, 58 | rspc 2862 | 
. . . . . . . . . 10
⊢ ((𝑘 + 1) ∈
(ℤ≥‘𝑀) → (∀𝑥 ∈ (ℤ≥‘𝑀)(∀𝑦 ∈ (𝑀...(𝑥 − 1))𝜓 → 𝜑) → (∀𝑦 ∈ (𝑀...((𝑘 + 1) − 1))𝜓 → [(𝑘 + 1) / 𝑥]𝜑))) | 
| 60 | 50, 21, 59 | mpisyl 1457 | 
. . . . . . . . 9
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (∀𝑦 ∈ (𝑀...((𝑘 + 1) − 1))𝜓 → [(𝑘 + 1) / 𝑥]𝜑)) | 
| 61 | 48, 60 | sylbird 170 | 
. . . . . . . 8
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (∀𝑦 ∈ (𝑀...𝑘)𝜓 → [(𝑘 + 1) / 𝑥]𝜑)) | 
| 62 | 41, 61 | mpd 13 | 
. . . . . . 7
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → [(𝑘 + 1) / 𝑥]𝜑) | 
| 63 | 42 | peano2zd 9451 | 
. . . . . . . . 9
⊢ (𝑘 ∈
(ℤ≥‘𝑀) → (𝑘 + 1) ∈ ℤ) | 
| 64 | 63 | adantr 276 | 
. . . . . . . 8
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (𝑘 + 1) ∈ ℤ) | 
| 65 |   | ralsns 3660 | 
. . . . . . . 8
⊢ ((𝑘 + 1) ∈ ℤ →
(∀𝑥 ∈ {(𝑘 + 1)}𝜑 ↔ [(𝑘 + 1) / 𝑥]𝜑)) | 
| 66 | 64, 65 | syl 14 | 
. . . . . . 7
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (∀𝑥 ∈ {(𝑘 + 1)}𝜑 ↔ [(𝑘 + 1) / 𝑥]𝜑)) | 
| 67 | 62, 66 | mpbird 167 | 
. . . . . 6
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → ∀𝑥 ∈ {(𝑘 + 1)}𝜑) | 
| 68 |   | ralun 3345 | 
. . . . . 6
⊢
((∀𝑥 ∈
(𝑀...𝑘)𝜑 ∧ ∀𝑥 ∈ {(𝑘 + 1)}𝜑) → ∀𝑥 ∈ ((𝑀...𝑘) ∪ {(𝑘 + 1)})𝜑) | 
| 69 | 38, 67, 68 | syl2anc 411 | 
. . . . 5
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → ∀𝑥 ∈ ((𝑀...𝑘) ∪ {(𝑘 + 1)})𝜑) | 
| 70 |   | fzsuc 10144 | 
. . . . . . 7
⊢ (𝑘 ∈
(ℤ≥‘𝑀) → (𝑀...(𝑘 + 1)) = ((𝑀...𝑘) ∪ {(𝑘 + 1)})) | 
| 71 | 70 | raleqdv 2699 | 
. . . . . 6
⊢ (𝑘 ∈
(ℤ≥‘𝑀) → (∀𝑥 ∈ (𝑀...(𝑘 + 1))𝜑 ↔ ∀𝑥 ∈ ((𝑀...𝑘) ∪ {(𝑘 + 1)})𝜑)) | 
| 72 | 71 | adantr 276 | 
. . . . 5
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → (∀𝑥 ∈ (𝑀...(𝑘 + 1))𝜑 ↔ ∀𝑥 ∈ ((𝑀...𝑘) ∪ {(𝑘 + 1)})𝜑)) | 
| 73 | 69, 72 | mpbird 167 | 
. . . 4
⊢ ((𝑘 ∈
(ℤ≥‘𝑀) ∧ ∀𝑥 ∈ (𝑀...𝑘)𝜑) → ∀𝑥 ∈ (𝑀...(𝑘 + 1))𝜑) | 
| 74 | 73 | ex 115 | 
. . 3
⊢ (𝑘 ∈
(ℤ≥‘𝑀) → (∀𝑥 ∈ (𝑀...𝑘)𝜑 → ∀𝑥 ∈ (𝑀...(𝑘 + 1))𝜑)) | 
| 75 | 3, 5, 7, 9, 37, 74 | uzind4 9662 | 
. 2
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → ∀𝑥 ∈ (𝑀...𝑁)𝜑) | 
| 76 |   | eluzfz2 10107 | 
. 2
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝑁 ∈ (𝑀...𝑁)) | 
| 77 | 1, 75, 76 | rspcdva 2873 | 
1
⊢ (𝑁 ∈
(ℤ≥‘𝑀) → 𝜒) |