| Step | Hyp | Ref | Expression | 
|---|
| 1 |  | fveq1 6905 | . . . . . . . 8
⊢ (𝑓 = 𝑔 → (𝑓‘𝑛) = (𝑔‘𝑛)) | 
| 2 | 1 | fveq2d 6910 | . . . . . . 7
⊢ (𝑓 = 𝑔 → (𝑇‘(𝑓‘𝑛)) = (𝑇‘(𝑔‘𝑛))) | 
| 3 | 2 | oveq2d 7447 | . . . . . 6
⊢ (𝑓 = 𝑔 → ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))) = ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))) | 
| 4 | 3 | mpteq2dv 5244 | . . . . 5
⊢ (𝑓 = 𝑔 → (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛)))) = (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛))))) | 
| 5 | 4 | oveq2d 7447 | . . . 4
⊢ (𝑓 = 𝑔 → (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) | 
| 6 | 5 | eqeq2d 2748 | . . 3
⊢ (𝑓 = 𝑔 → (𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) ↔ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛))))))) | 
| 7 | 6 | cbvrexvw 3238 | . 2
⊢
(∃𝑓 ∈
(𝐷 ↑m
{0})𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) ↔ ∃𝑔 ∈ (𝐷 ↑m {0})𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) | 
| 8 |  | crngring 20242 | . . . . . . . 8
⊢ (𝑅 ∈ CRing → 𝑅 ∈ Ring) | 
| 9 | 8 | anim2i 617 | . . . . . . 7
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing) → (𝑁 ∈ Fin ∧ 𝑅 ∈ Ring)) | 
| 10 | 9 | 3adant3 1133 | . . . . . 6
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) → (𝑁 ∈ Fin ∧ 𝑅 ∈ Ring)) | 
| 11 | 10 | ad2antrr 726 | . . . . 5
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → (𝑁 ∈ Fin ∧ 𝑅 ∈ Ring)) | 
| 12 |  | simplr 769 | . . . . 5
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → 𝑔 ∈ (𝐷 ↑m {0})) | 
| 13 |  | simpr 484 | . . . . 5
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) | 
| 14 |  | pmatcollpw.p | . . . . . 6
⊢ 𝑃 = (Poly1‘𝑅) | 
| 15 |  | pmatcollpw.c | . . . . . 6
⊢ 𝐶 = (𝑁 Mat 𝑃) | 
| 16 |  | pmatcollpw.b | . . . . . 6
⊢ 𝐵 = (Base‘𝐶) | 
| 17 |  | pmatcollpw.m | . . . . . 6
⊢  ∗ = (
·𝑠 ‘𝐶) | 
| 18 |  | pmatcollpw.e | . . . . . 6
⊢  ↑ =
(.g‘(mulGrp‘𝑃)) | 
| 19 |  | pmatcollpw.x | . . . . . 6
⊢ 𝑋 = (var1‘𝑅) | 
| 20 |  | pmatcollpw.t | . . . . . 6
⊢ 𝑇 = (𝑁 matToPolyMat 𝑅) | 
| 21 |  | pmatcollpw3.a | . . . . . 6
⊢ 𝐴 = (𝑁 Mat 𝑅) | 
| 22 |  | pmatcollpw3.d | . . . . . 6
⊢ 𝐷 = (Base‘𝐴) | 
| 23 |  | eqid 2737 | . . . . . 6
⊢
(0g‘𝐴) = (0g‘𝐴) | 
| 24 |  | eqid 2737 | . . . . . 6
⊢ (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) | 
| 25 | 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24 | pmatcollpw3fi1lem1 22792 | . . . . 5
⊢ (((𝑁 ∈ Fin ∧ 𝑅 ∈ Ring) ∧ 𝑔 ∈ (𝐷 ↑m {0}) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))))) | 
| 26 | 11, 12, 13, 25 | syl3anc 1373 | . . . 4
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))))) | 
| 27 |  | 1nn 12277 | . . . . . 6
⊢ 1 ∈
ℕ | 
| 28 | 27 | a1i 11 | . . . . 5
⊢
(((((𝑁 ∈ Fin
∧ 𝑅 ∈ CRing ∧
𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))))) → 1 ∈
ℕ) | 
| 29 |  | oveq2 7439 | . . . . . . . 8
⊢ (𝑠 = 1 → (0...𝑠) = (0...1)) | 
| 30 | 29 | oveq2d 7447 | . . . . . . 7
⊢ (𝑠 = 1 → (𝐷 ↑m (0...𝑠)) = (𝐷 ↑m
(0...1))) | 
| 31 | 29 | mpteq1d 5237 | . . . . . . . . 9
⊢ (𝑠 = 1 → (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛)))) = (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) | 
| 32 | 31 | oveq2d 7447 | . . . . . . . 8
⊢ (𝑠 = 1 → (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛)))))) | 
| 33 | 32 | eqeq2d 2748 | . . . . . . 7
⊢ (𝑠 = 1 → (𝑀 = (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) ↔ 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))))) | 
| 34 | 30, 33 | rexeqbidv 3347 | . . . . . 6
⊢ (𝑠 = 1 → (∃𝑓 ∈ (𝐷 ↑m (0...𝑠))𝑀 = (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) ↔ ∃𝑓 ∈ (𝐷 ↑m (0...1))𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))))) | 
| 35 | 34 | adantl 481 | . . . . 5
⊢
((((((𝑁 ∈ Fin
∧ 𝑅 ∈ CRing ∧
𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))))) ∧ 𝑠 = 1) → (∃𝑓 ∈ (𝐷 ↑m (0...𝑠))𝑀 = (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) ↔ ∃𝑓 ∈ (𝐷 ↑m (0...1))𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))))) | 
| 36 |  | elmapi 8889 | . . . . . . . . . . . . . 14
⊢ (𝑔 ∈ (𝐷 ↑m {0}) → 𝑔:{0}⟶𝐷) | 
| 37 |  | c0ex 11255 | . . . . . . . . . . . . . . . . . 18
⊢ 0 ∈
V | 
| 38 | 37 | snid 4662 | . . . . . . . . . . . . . . . . 17
⊢ 0 ∈
{0} | 
| 39 | 38 | a1i 11 | . . . . . . . . . . . . . . . 16
⊢ (𝑙 ∈ (0...1) → 0 ∈
{0}) | 
| 40 |  | ffvelcdm 7101 | . . . . . . . . . . . . . . . 16
⊢ ((𝑔:{0}⟶𝐷 ∧ 0 ∈ {0}) → (𝑔‘0) ∈ 𝐷) | 
| 41 | 39, 40 | sylan2 593 | . . . . . . . . . . . . . . 15
⊢ ((𝑔:{0}⟶𝐷 ∧ 𝑙 ∈ (0...1)) → (𝑔‘0) ∈ 𝐷) | 
| 42 | 41 | ex 412 | . . . . . . . . . . . . . 14
⊢ (𝑔:{0}⟶𝐷 → (𝑙 ∈ (0...1) → (𝑔‘0) ∈ 𝐷)) | 
| 43 | 36, 42 | syl 17 | . . . . . . . . . . . . 13
⊢ (𝑔 ∈ (𝐷 ↑m {0}) → (𝑙 ∈ (0...1) → (𝑔‘0) ∈ 𝐷)) | 
| 44 | 43 | adantl 481 | . . . . . . . . . . . 12
⊢ (((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) → (𝑙 ∈ (0...1) → (𝑔‘0) ∈ 𝐷)) | 
| 45 | 44 | imp 406 | . . . . . . . . . . 11
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑙 ∈ (0...1)) → (𝑔‘0) ∈ 𝐷) | 
| 46 | 21 | matring 22449 | . . . . . . . . . . . . . . 15
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ Ring) → 𝐴 ∈ Ring) | 
| 47 | 8, 46 | sylan2 593 | . . . . . . . . . . . . . 14
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing) → 𝐴 ∈ Ring) | 
| 48 | 47 | 3adant3 1133 | . . . . . . . . . . . . 13
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) → 𝐴 ∈ Ring) | 
| 49 | 22, 23 | ring0cl 20264 | . . . . . . . . . . . . 13
⊢ (𝐴 ∈ Ring →
(0g‘𝐴)
∈ 𝐷) | 
| 50 | 48, 49 | syl 17 | . . . . . . . . . . . 12
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) → (0g‘𝐴) ∈ 𝐷) | 
| 51 | 50 | ad2antrr 726 | . . . . . . . . . . 11
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑙 ∈ (0...1)) →
(0g‘𝐴)
∈ 𝐷) | 
| 52 | 45, 51 | ifcld 4572 | . . . . . . . . . 10
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑙 ∈ (0...1)) → if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)) ∈ 𝐷) | 
| 53 | 52 | fmpttd 7135 | . . . . . . . . 9
⊢ (((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) → (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))):(0...1)⟶𝐷) | 
| 54 | 22 | fvexi 6920 | . . . . . . . . . . 11
⊢ 𝐷 ∈ V | 
| 55 |  | ovex 7464 | . . . . . . . . . . 11
⊢ (0...1)
∈ V | 
| 56 | 54, 55 | pm3.2i 470 | . . . . . . . . . 10
⊢ (𝐷 ∈ V ∧ (0...1) ∈
V) | 
| 57 |  | elmapg 8879 | . . . . . . . . . 10
⊢ ((𝐷 ∈ V ∧ (0...1) ∈
V) → ((𝑙 ∈
(0...1) ↦ if(𝑙 = 0,
(𝑔‘0),
(0g‘𝐴)))
∈ (𝐷
↑m (0...1)) ↔ (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))):(0...1)⟶𝐷)) | 
| 58 | 56, 57 | mp1i 13 | . . . . . . . . 9
⊢ (((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) → ((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) ∈ (𝐷 ↑m (0...1)) ↔ (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))):(0...1)⟶𝐷)) | 
| 59 | 53, 58 | mpbird 257 | . . . . . . . 8
⊢ (((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) → (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) ∈ (𝐷 ↑m
(0...1))) | 
| 60 | 59 | adantr 480 | . . . . . . 7
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) ∈ (𝐷 ↑m
(0...1))) | 
| 61 |  | fveq1 6905 | . . . . . . . . . . . . 13
⊢ (𝑓 = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) → (𝑓‘𝑛) = ((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)) | 
| 62 | 61 | fveq2d 6910 | . . . . . . . . . . . 12
⊢ (𝑓 = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) → (𝑇‘(𝑓‘𝑛)) = (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛))) | 
| 63 | 62 | oveq2d 7447 | . . . . . . . . . . 11
⊢ (𝑓 = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) → ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))) = ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))) | 
| 64 | 63 | mpteq2dv 5244 | . . . . . . . . . 10
⊢ (𝑓 = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) → (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛)))) = (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛))))) | 
| 65 | 64 | oveq2d 7447 | . . . . . . . . 9
⊢ (𝑓 = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) → (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))))) | 
| 66 | 65 | eqeq2d 2748 | . . . . . . . 8
⊢ (𝑓 = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴))) → (𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) ↔ 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛))))))) | 
| 67 | 66 | adantl 481 | . . . . . . 7
⊢
(((((𝑁 ∈ Fin
∧ 𝑅 ∈ CRing ∧
𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) ∧ 𝑓 = (𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))) → (𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) ↔ 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛))))))) | 
| 68 | 60, 67 | rspcedv 3615 | . . . . . 6
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → (𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛))))) → ∃𝑓 ∈ (𝐷 ↑m (0...1))𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))))) | 
| 69 | 68 | imp 406 | . . . . 5
⊢
(((((𝑁 ∈ Fin
∧ 𝑅 ∈ CRing ∧
𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))))) → ∃𝑓 ∈ (𝐷 ↑m (0...1))𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛)))))) | 
| 70 | 28, 35, 69 | rspcedvd 3624 | . . . 4
⊢
(((((𝑁 ∈ Fin
∧ 𝑅 ∈ CRing ∧
𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ (0...1) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘((𝑙 ∈ (0...1) ↦ if(𝑙 = 0, (𝑔‘0), (0g‘𝐴)))‘𝑛)))))) → ∃𝑠 ∈ ℕ ∃𝑓 ∈ (𝐷 ↑m (0...𝑠))𝑀 = (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛)))))) | 
| 71 | 26, 70 | mpdan 687 | . . 3
⊢ ((((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) ∧ 𝑔 ∈ (𝐷 ↑m {0})) ∧ 𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛)))))) → ∃𝑠 ∈ ℕ ∃𝑓 ∈ (𝐷 ↑m (0...𝑠))𝑀 = (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛)))))) | 
| 72 | 71 | rexlimdva2 3157 | . 2
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) → (∃𝑔 ∈ (𝐷 ↑m {0})𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑔‘𝑛))))) → ∃𝑠 ∈ ℕ ∃𝑓 ∈ (𝐷 ↑m (0...𝑠))𝑀 = (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))))) | 
| 73 | 7, 72 | biimtrid 242 | 1
⊢ ((𝑁 ∈ Fin ∧ 𝑅 ∈ CRing ∧ 𝑀 ∈ 𝐵) → (∃𝑓 ∈ (𝐷 ↑m {0})𝑀 = (𝐶 Σg (𝑛 ∈ {0} ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))) → ∃𝑠 ∈ ℕ ∃𝑓 ∈ (𝐷 ↑m (0...𝑠))𝑀 = (𝐶 Σg (𝑛 ∈ (0...𝑠) ↦ ((𝑛 ↑ 𝑋) ∗ (𝑇‘(𝑓‘𝑛))))))) |