| Step | Hyp | Ref
 | Expression | 
| 1 |   | elply 14970 | 
. . 3
⊢ (𝐹 ∈ (Poly‘𝑆) ↔ (𝑆 ⊆ ℂ ∧ ∃𝑛 ∈ ℕ0
∃𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))))) | 
| 2 |   | simpr 110 | 
. . . . . . . . . . . . 13
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → 𝑓 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)) | 
| 3 |   | simpll 527 | 
. . . . . . . . . . . . . . . 16
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → 𝑆 ⊆ ℂ) | 
| 4 |   | cnex 8003 | 
. . . . . . . . . . . . . . . 16
⊢ ℂ
∈ V | 
| 5 |   | ssexg 4172 | 
. . . . . . . . . . . . . . . 16
⊢ ((𝑆 ⊆ ℂ ∧ ℂ
∈ V) → 𝑆 ∈
V) | 
| 6 | 3, 4, 5 | sylancl 413 | 
. . . . . . . . . . . . . . 15
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → 𝑆 ∈ V) | 
| 7 |   | c0ex 8020 | 
. . . . . . . . . . . . . . . 16
⊢ 0 ∈
V | 
| 8 | 7 | snex 4218 | 
. . . . . . . . . . . . . . 15
⊢ {0}
∈ V | 
| 9 |   | unexg 4478 | 
. . . . . . . . . . . . . . 15
⊢ ((𝑆 ∈ V ∧ {0} ∈ V)
→ (𝑆 ∪ {0}) ∈
V) | 
| 10 | 6, 8, 9 | sylancl 413 | 
. . . . . . . . . . . . . 14
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → (𝑆 ∪ {0}) ∈ V) | 
| 11 |   | nn0ex 9255 | 
. . . . . . . . . . . . . 14
⊢
ℕ0 ∈ V | 
| 12 |   | elmapg 6720 | 
. . . . . . . . . . . . . 14
⊢ (((𝑆 ∪ {0}) ∈ V ∧
ℕ0 ∈ V) → (𝑓 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0) ↔ 𝑓:ℕ0⟶(𝑆 ∪ {0}))) | 
| 13 | 10, 11, 12 | sylancl 413 | 
. . . . . . . . . . . . 13
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → (𝑓 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0) ↔ 𝑓:ℕ0⟶(𝑆 ∪ {0}))) | 
| 14 | 2, 13 | mpbid 147 | 
. . . . . . . . . . . 12
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → 𝑓:ℕ0⟶(𝑆 ∪ {0})) | 
| 15 | 14 | ffvelcdmda 5697 | 
. . . . . . . . . . 11
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) → (𝑓‘𝑥) ∈ (𝑆 ∪ {0})) | 
| 16 |   | ssun2 3327 | 
. . . . . . . . . . . . 13
⊢ {0}
⊆ (𝑆 ∪
{0}) | 
| 17 | 7 | snss 3757 | 
. . . . . . . . . . . . 13
⊢ (0 ∈
(𝑆 ∪ {0}) ↔ {0}
⊆ (𝑆 ∪
{0})) | 
| 18 | 16, 17 | mpbir 146 | 
. . . . . . . . . . . 12
⊢ 0 ∈
(𝑆 ∪
{0}) | 
| 19 | 18 | a1i 9 | 
. . . . . . . . . . 11
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) → 0 ∈
(𝑆 ∪
{0})) | 
| 20 |   | nn0z 9346 | 
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ ℕ0
→ 𝑥 ∈
ℤ) | 
| 21 | 20 | adantl 277 | 
. . . . . . . . . . . 12
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) → 𝑥 ∈
ℤ) | 
| 22 |   | 0zd 9338 | 
. . . . . . . . . . . 12
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) → 0 ∈
ℤ) | 
| 23 |   | simpllr 534 | 
. . . . . . . . . . . . 13
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) → 𝑛 ∈
ℕ0) | 
| 24 | 23 | nn0zd 9446 | 
. . . . . . . . . . . 12
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) → 𝑛 ∈
ℤ) | 
| 25 |   | fzdcel 10115 | 
. . . . . . . . . . . 12
⊢ ((𝑥 ∈ ℤ ∧ 0 ∈
ℤ ∧ 𝑛 ∈
ℤ) → DECID 𝑥 ∈ (0...𝑛)) | 
| 26 | 21, 22, 24, 25 | syl3anc 1249 | 
. . . . . . . . . . 11
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) →
DECID 𝑥
∈ (0...𝑛)) | 
| 27 | 15, 19, 26 | ifcldcd 3597 | 
. . . . . . . . . 10
⊢ ((((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) ∧ 𝑥 ∈ ℕ0) → if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0) ∈ (𝑆 ∪ {0})) | 
| 28 | 27 | fmpttd 5717 | 
. . . . . . . . 9
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)):ℕ0⟶(𝑆 ∪ {0})) | 
| 29 |   | elmapg 6720 | 
. . . . . . . . . 10
⊢ (((𝑆 ∪ {0}) ∈ V ∧
ℕ0 ∈ V) → ((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0) ↔ (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)):ℕ0⟶(𝑆 ∪ {0}))) | 
| 30 | 10, 11, 29 | sylancl 413 | 
. . . . . . . . 9
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → ((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0) ↔ (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)):ℕ0⟶(𝑆 ∪ {0}))) | 
| 31 | 28, 30 | mpbird 167 | 
. . . . . . . 8
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)) | 
| 32 |   | mptima 5021 | 
. . . . . . . . . 10
⊢ ((𝑥 ∈ ℕ0
↦ if(𝑥 ∈
(0...𝑛), (𝑓‘𝑥), 0)) “
(ℤ≥‘(𝑛 + 1))) = ran (𝑥 ∈ (ℕ0 ∩
(ℤ≥‘(𝑛 + 1))) ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) | 
| 33 |   | fznuz 10177 | 
. . . . . . . . . . . . . . . 16
⊢ (𝑥 ∈ (0...𝑛) → ¬ 𝑥 ∈ (ℤ≥‘(𝑛 + 1))) | 
| 34 |   | elinel2 3350 | 
. . . . . . . . . . . . . . . 16
⊢ (𝑥 ∈ (ℕ0
∩ (ℤ≥‘(𝑛 + 1))) → 𝑥 ∈ (ℤ≥‘(𝑛 + 1))) | 
| 35 | 33, 34 | nsyl3 627 | 
. . . . . . . . . . . . . . 15
⊢ (𝑥 ∈ (ℕ0
∩ (ℤ≥‘(𝑛 + 1))) → ¬ 𝑥 ∈ (0...𝑛)) | 
| 36 | 35 | iffalsed 3571 | 
. . . . . . . . . . . . . 14
⊢ (𝑥 ∈ (ℕ0
∩ (ℤ≥‘(𝑛 + 1))) → if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0) = 0) | 
| 37 | 36 | mpteq2ia 4119 | 
. . . . . . . . . . . . 13
⊢ (𝑥 ∈ (ℕ0
∩ (ℤ≥‘(𝑛 + 1))) ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) = (𝑥 ∈ (ℕ0 ∩
(ℤ≥‘(𝑛 + 1))) ↦ 0) | 
| 38 |   | fconstmpt 4710 | 
. . . . . . . . . . . . 13
⊢
((ℕ0 ∩ (ℤ≥‘(𝑛 + 1))) × {0}) = (𝑥 ∈ (ℕ0
∩ (ℤ≥‘(𝑛 + 1))) ↦ 0) | 
| 39 | 37, 38 | eqtr4i 2220 | 
. . . . . . . . . . . 12
⊢ (𝑥 ∈ (ℕ0
∩ (ℤ≥‘(𝑛 + 1))) ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) = ((ℕ0 ∩
(ℤ≥‘(𝑛 + 1))) × {0}) | 
| 40 | 39 | rneqi 4894 | 
. . . . . . . . . . 11
⊢ ran
(𝑥 ∈
(ℕ0 ∩ (ℤ≥‘(𝑛 + 1))) ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) = ran ((ℕ0 ∩
(ℤ≥‘(𝑛 + 1))) × {0}) | 
| 41 |   | peano2nn0 9289 | 
. . . . . . . . . . . . 13
⊢ (𝑛 ∈ ℕ0
→ (𝑛 + 1) ∈
ℕ0) | 
| 42 |   | nn0z 9346 | 
. . . . . . . . . . . . . . 15
⊢ (𝑛 ∈ ℕ0
→ 𝑛 ∈
ℤ) | 
| 43 | 42 | peano2zd 9451 | 
. . . . . . . . . . . . . 14
⊢ (𝑛 ∈ ℕ0
→ (𝑛 + 1) ∈
ℤ) | 
| 44 | 43 | uzidd 9616 | 
. . . . . . . . . . . . 13
⊢ (𝑛 ∈ ℕ0
→ (𝑛 + 1) ∈
(ℤ≥‘(𝑛 + 1))) | 
| 45 | 41, 44 | elind 3348 | 
. . . . . . . . . . . 12
⊢ (𝑛 ∈ ℕ0
→ (𝑛 + 1) ∈
(ℕ0 ∩ (ℤ≥‘(𝑛 + 1)))) | 
| 46 |   | elex2 2779 | 
. . . . . . . . . . . 12
⊢ ((𝑛 + 1) ∈
(ℕ0 ∩ (ℤ≥‘(𝑛 + 1))) → ∃𝑤 𝑤 ∈ (ℕ0 ∩
(ℤ≥‘(𝑛 + 1)))) | 
| 47 |   | rnxpm 5099 | 
. . . . . . . . . . . 12
⊢
(∃𝑤 𝑤 ∈ (ℕ0
∩ (ℤ≥‘(𝑛 + 1))) → ran ((ℕ0
∩ (ℤ≥‘(𝑛 + 1))) × {0}) = {0}) | 
| 48 | 45, 46, 47 | 3syl 17 | 
. . . . . . . . . . 11
⊢ (𝑛 ∈ ℕ0
→ ran ((ℕ0 ∩ (ℤ≥‘(𝑛 + 1))) × {0}) =
{0}) | 
| 49 | 40, 48 | eqtrid 2241 | 
. . . . . . . . . 10
⊢ (𝑛 ∈ ℕ0
→ ran (𝑥 ∈
(ℕ0 ∩ (ℤ≥‘(𝑛 + 1))) ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) = {0}) | 
| 50 | 32, 49 | eqtrid 2241 | 
. . . . . . . . 9
⊢ (𝑛 ∈ ℕ0
→ ((𝑥 ∈
ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) “
(ℤ≥‘(𝑛 + 1))) = {0}) | 
| 51 | 50 | ad2antlr 489 | 
. . . . . . . 8
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → ((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) “
(ℤ≥‘(𝑛 + 1))) = {0}) | 
| 52 |   | eqidd 2197 | 
. . . . . . . 8
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘)))) | 
| 53 |   | imaeq1 5004 | 
. . . . . . . . . . 11
⊢ (𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) → (𝑎 “ (ℤ≥‘(𝑛 + 1))) = ((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) “
(ℤ≥‘(𝑛 + 1)))) | 
| 54 | 53 | eqeq1d 2205 | 
. . . . . . . . . 10
⊢ (𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) → ((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ↔ ((𝑥 ∈ ℕ0
↦ if(𝑥 ∈
(0...𝑛), (𝑓‘𝑥), 0)) “
(ℤ≥‘(𝑛 + 1))) = {0})) | 
| 55 |   | fveq1 5557 | 
. . . . . . . . . . . . . . 15
⊢ (𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) → (𝑎‘𝑘) = ((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0))‘𝑘)) | 
| 56 |   | elfznn0 10189 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝑘 ∈ (0...𝑛) → 𝑘 ∈ ℕ0) | 
| 57 |   | eleq1w 2257 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑥 = 𝑘 → (𝑥 ∈ (0...𝑛) ↔ 𝑘 ∈ (0...𝑛))) | 
| 58 |   | fveq2 5558 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑥 = 𝑘 → (𝑓‘𝑥) = (𝑓‘𝑘)) | 
| 59 | 57, 58 | ifbieq1d 3583 | 
. . . . . . . . . . . . . . . . . 18
⊢ (𝑥 = 𝑘 → if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0) = if(𝑘 ∈ (0...𝑛), (𝑓‘𝑘), 0)) | 
| 60 |   | eqid 2196 | 
. . . . . . . . . . . . . . . . . 18
⊢ (𝑥 ∈ ℕ0
↦ if(𝑥 ∈
(0...𝑛), (𝑓‘𝑥), 0)) = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) | 
| 61 |   | vex 2766 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ 𝑓 ∈ V | 
| 62 |   | vex 2766 | 
. . . . . . . . . . . . . . . . . . . 20
⊢ 𝑘 ∈ V | 
| 63 | 61, 62 | fvex 5578 | 
. . . . . . . . . . . . . . . . . . 19
⊢ (𝑓‘𝑘) ∈ V | 
| 64 | 63, 7 | ifex 4521 | 
. . . . . . . . . . . . . . . . . 18
⊢ if(𝑘 ∈ (0...𝑛), (𝑓‘𝑘), 0) ∈ V | 
| 65 | 59, 60, 64 | fvmpt 5638 | 
. . . . . . . . . . . . . . . . 17
⊢ (𝑘 ∈ ℕ0
→ ((𝑥 ∈
ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0))‘𝑘) = if(𝑘 ∈ (0...𝑛), (𝑓‘𝑘), 0)) | 
| 66 | 56, 65 | syl 14 | 
. . . . . . . . . . . . . . . 16
⊢ (𝑘 ∈ (0...𝑛) → ((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0))‘𝑘) = if(𝑘 ∈ (0...𝑛), (𝑓‘𝑘), 0)) | 
| 67 |   | iftrue 3566 | 
. . . . . . . . . . . . . . . 16
⊢ (𝑘 ∈ (0...𝑛) → if(𝑘 ∈ (0...𝑛), (𝑓‘𝑘), 0) = (𝑓‘𝑘)) | 
| 68 | 66, 67 | eqtrd 2229 | 
. . . . . . . . . . . . . . 15
⊢ (𝑘 ∈ (0...𝑛) → ((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0))‘𝑘) = (𝑓‘𝑘)) | 
| 69 | 55, 68 | sylan9eq 2249 | 
. . . . . . . . . . . . . 14
⊢ ((𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) ∧ 𝑘 ∈ (0...𝑛)) → (𝑎‘𝑘) = (𝑓‘𝑘)) | 
| 70 | 69 | oveq1d 5937 | 
. . . . . . . . . . . . 13
⊢ ((𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) ∧ 𝑘 ∈ (0...𝑛)) → ((𝑎‘𝑘) · (𝑧↑𝑘)) = ((𝑓‘𝑘) · (𝑧↑𝑘))) | 
| 71 | 70 | sumeq2dv 11533 | 
. . . . . . . . . . . 12
⊢ (𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) → Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)) = Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) | 
| 72 | 71 | mpteq2dv 4124 | 
. . . . . . . . . . 11
⊢ (𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) → (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘)))) | 
| 73 | 72 | eqeq2d 2208 | 
. . . . . . . . . 10
⊢ (𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) → ((𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))) ↔ (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))))) | 
| 74 | 54, 73 | anbi12d 473 | 
. . . . . . . . 9
⊢ (𝑎 = (𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) → (((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ∧ (𝑧 ∈ ℂ ↦
Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) ↔ (((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) “
(ℤ≥‘(𝑛 + 1))) = {0} ∧ (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘)))))) | 
| 75 | 74 | rspcev 2868 | 
. . . . . . . 8
⊢ (((𝑥 ∈ ℕ0
↦ if(𝑥 ∈
(0...𝑛), (𝑓‘𝑥), 0)) ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0) ∧ (((𝑥 ∈ ℕ0 ↦ if(𝑥 ∈ (0...𝑛), (𝑓‘𝑥), 0)) “
(ℤ≥‘(𝑛 + 1))) = {0} ∧ (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))))) → ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))))) | 
| 76 | 31, 51, 52, 75 | syl12anc 1247 | 
. . . . . . 7
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))))) | 
| 77 |   | eqeq1 2203 | 
. . . . . . . . 9
⊢ (𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) → (𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))) ↔ (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))))) | 
| 78 | 77 | anbi2d 464 | 
. . . . . . . 8
⊢ (𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) → (((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) ↔ ((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ∧ (𝑧 ∈ ℂ ↦
Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) | 
| 79 | 78 | rexbidv 2498 | 
. . . . . . 7
⊢ (𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) → (∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) ↔ ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) | 
| 80 | 76, 79 | syl5ibrcom 157 | 
. . . . . 6
⊢ (((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
∧ 𝑓 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)) → (𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) → ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) | 
| 81 | 80 | rexlimdva 2614 | 
. . . . 5
⊢ ((𝑆 ⊆ ℂ ∧ 𝑛 ∈ ℕ0)
→ (∃𝑓 ∈
((𝑆 ∪ {0})
↑𝑚 ℕ0)𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) → ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) | 
| 82 | 81 | reximdva 2599 | 
. . . 4
⊢ (𝑆 ⊆ ℂ →
(∃𝑛 ∈
ℕ0 ∃𝑓 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)𝐹 =
(𝑧 ∈ ℂ ↦
Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘))) → ∃𝑛 ∈ ℕ0 ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) | 
| 83 | 82 | imdistani 445 | 
. . 3
⊢ ((𝑆 ⊆ ℂ ∧
∃𝑛 ∈
ℕ0 ∃𝑓 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)𝐹 =
(𝑧 ∈ ℂ ↦
Σ𝑘 ∈ (0...𝑛)((𝑓‘𝑘) · (𝑧↑𝑘)))) → (𝑆 ⊆ ℂ ∧ ∃𝑛 ∈ ℕ0
∃𝑎 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) | 
| 84 | 1, 83 | sylbi 121 | 
. 2
⊢ (𝐹 ∈ (Poly‘𝑆) → (𝑆 ⊆ ℂ ∧ ∃𝑛 ∈ ℕ0
∃𝑎 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) | 
| 85 |   | simpr 110 | 
. . . . . 6
⊢ (((𝑎 “
(ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) → 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) | 
| 86 | 85 | reximi 2594 | 
. . . . 5
⊢
(∃𝑎 ∈
((𝑆 ∪ {0})
↑𝑚 ℕ0)((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) → ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)𝐹 =
(𝑧 ∈ ℂ ↦
Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) | 
| 87 | 86 | reximi 2594 | 
. . . 4
⊢
(∃𝑛 ∈
ℕ0 ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) → ∃𝑛 ∈ ℕ0 ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)𝐹 =
(𝑧 ∈ ℂ ↦
Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))) | 
| 88 | 87 | anim2i 342 | 
. . 3
⊢ ((𝑆 ⊆ ℂ ∧
∃𝑛 ∈
ℕ0 ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))))) → (𝑆 ⊆ ℂ ∧ ∃𝑛 ∈ ℕ0
∃𝑎 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))))) | 
| 89 |   | elply 14970 | 
. . 3
⊢ (𝐹 ∈ (Poly‘𝑆) ↔ (𝑆 ⊆ ℂ ∧ ∃𝑛 ∈ ℕ0
∃𝑎 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))))) | 
| 90 | 88, 89 | sylibr 134 | 
. 2
⊢ ((𝑆 ⊆ ℂ ∧
∃𝑛 ∈
ℕ0 ∃𝑎 ∈ ((𝑆 ∪ {0}) ↑𝑚
ℕ0)((𝑎
“ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘))))) → 𝐹 ∈ (Poly‘𝑆)) | 
| 91 | 84, 90 | impbii 126 | 
1
⊢ (𝐹 ∈ (Poly‘𝑆) ↔ (𝑆 ⊆ ℂ ∧ ∃𝑛 ∈ ℕ0
∃𝑎 ∈ ((𝑆 ∪ {0})
↑𝑚 ℕ0)((𝑎 “ (ℤ≥‘(𝑛 + 1))) = {0} ∧ 𝐹 = (𝑧 ∈ ℂ ↦ Σ𝑘 ∈ (0...𝑛)((𝑎‘𝑘) · (𝑧↑𝑘)))))) |