Metamath Proof Explorer


Theorem isumshft

Description: Index shift of an infinite sum. (Contributed by Paul Chapman, 31-Oct-2007) (Revised by Mario Carneiro, 24-Apr-2014)

Ref Expression
Hypotheses isumshft.1 ⊢ Z = ℤ ≥ M
isumshft.2 ⊢ W = ℤ ≥ M + K
isumshft.3 ⊢ j = K + k → A = B
isumshft.4 ⊢ φ → K ∈ ℤ
isumshft.5 ⊢ φ → M ∈ ℤ
isumshft.6 ⊢ φ ∧ j ∈ W → A ∈ ℂ
Assertion isumshft ⊢ φ → ∑ j ∈ W A = ∑ k ∈ Z B

Proof

Step Hyp Ref Expression
1 isumshft.1 ⊢ Z = ℤ ≥ M
2 isumshft.2 ⊢ W = ℤ ≥ M + K
3 isumshft.3 ⊢ j = K + k → A = B
4 isumshft.4 ⊢ φ → K ∈ ℤ
5 isumshft.5 ⊢ φ → M ∈ ℤ
6 isumshft.6 ⊢ φ ∧ j ∈ W → A ∈ ℂ
7 5 4 zaddcld ⊢ φ → M + K ∈ ℤ
8 2 eleq2i ⊢ m ∈ W ↔ m ∈ ℤ ≥ M + K
9 4 zcnd ⊢ φ → K ∈ ℂ
10 eluzelcn ⊢ m ∈ ℤ ≥ M + K → m ∈ ℂ
11 10 2 eleq2s ⊢ m ∈ W → m ∈ ℂ
12 1 fvexi ⊢ Z ∈ V
13 12 mptex ⊢ k ∈ Z ⟼ B ∈ V
14 13 shftval ⊢ K ∈ ℂ ∧ m ∈ ℂ → k ∈ Z ⟼ B shift K ⁡ m = k ∈ Z ⟼ B ⁡ m − K
15 9 11 14 syl2an ⊢ φ ∧ m ∈ W → k ∈ Z ⟼ B shift K ⁡ m = k ∈ Z ⟼ B ⁡ m − K
16 simpr ⊢ φ ∧ k ∈ Z → k ∈ Z
17 eqid ⊢ k ∈ Z ⟼ B = k ∈ Z ⟼ B
18 17 fvmpt2i ⊢ k ∈ Z → k ∈ Z ⟼ B ⁡ k = I ⁡ B
19 16 18 syl ⊢ φ ∧ k ∈ Z → k ∈ Z ⟼ B ⁡ k = I ⁡ B
20 eluzelcn ⊢ k ∈ ℤ ≥ M → k ∈ ℂ
21 20 1 eleq2s ⊢ k ∈ Z → k ∈ ℂ
22 addcom ⊢ K ∈ ℂ ∧ k ∈ ℂ → K + k = k + K
23 9 21 22 syl2an ⊢ φ ∧ k ∈ Z → K + k = k + K
24 id ⊢ k ∈ Z → k ∈ Z
25 24 1 eleqtrdi ⊢ k ∈ Z → k ∈ ℤ ≥ M
26 eluzadd ⊢ k ∈ ℤ ≥ M ∧ K ∈ ℤ → k + K ∈ ℤ ≥ M + K
27 25 4 26 syl2anr ⊢ φ ∧ k ∈ Z → k + K ∈ ℤ ≥ M + K
28 23 27 eqeltrd ⊢ φ ∧ k ∈ Z → K + k ∈ ℤ ≥ M + K
29 28 2 eleqtrrdi ⊢ φ ∧ k ∈ Z → K + k ∈ W
30 eqid ⊢ j ∈ W ⟼ A = j ∈ W ⟼ A
31 3 30 fvmpti ⊢ K + k ∈ W → j ∈ W ⟼ A ⁡ K + k = I ⁡ B
32 29 31 syl ⊢ φ ∧ k ∈ Z → j ∈ W ⟼ A ⁡ K + k = I ⁡ B
33 19 32 eqtr4d ⊢ φ ∧ k ∈ Z → k ∈ Z ⟼ B ⁡ k = j ∈ W ⟼ A ⁡ K + k
34 33 ralrimiva ⊢ φ → ∀ k ∈ Z k ∈ Z ⟼ B ⁡ k = j ∈ W ⟼ A ⁡ K + k
35 nffvmpt1 ⊢ Ⅎ _ k k ∈ Z ⟼ B ⁡ n
36 35 nfeq1 ⊢ Ⅎ k k ∈ Z ⟼ B ⁡ n = j ∈ W ⟼ A ⁡ K + n
37 fveq2 ⊢ k = n → k ∈ Z ⟼ B ⁡ k = k ∈ Z ⟼ B ⁡ n
38 oveq2 ⊢ k = n → K + k = K + n
39 38 fveq2d ⊢ k = n → j ∈ W ⟼ A ⁡ K + k = j ∈ W ⟼ A ⁡ K + n
40 37 39 eqeq12d ⊢ k = n → k ∈ Z ⟼ B ⁡ k = j ∈ W ⟼ A ⁡ K + k ↔ k ∈ Z ⟼ B ⁡ n = j ∈ W ⟼ A ⁡ K + n
41 36 40 rspc ⊢ n ∈ Z → ∀ k ∈ Z k ∈ Z ⟼ B ⁡ k = j ∈ W ⟼ A ⁡ K + k → k ∈ Z ⟼ B ⁡ n = j ∈ W ⟼ A ⁡ K + n
42 34 41 mpan9 ⊢ φ ∧ n ∈ Z → k ∈ Z ⟼ B ⁡ n = j ∈ W ⟼ A ⁡ K + n
43 42 ralrimiva ⊢ φ → ∀ n ∈ Z k ∈ Z ⟼ B ⁡ n = j ∈ W ⟼ A ⁡ K + n
44 5 adantr ⊢ φ ∧ m ∈ W → M ∈ ℤ
45 4 adantr ⊢ φ ∧ m ∈ W → K ∈ ℤ
46 simpr ⊢ φ ∧ m ∈ W → m ∈ W
47 46 2 eleqtrdi ⊢ φ ∧ m ∈ W → m ∈ ℤ ≥ M + K
48 eluzsub ⊢ M ∈ ℤ ∧ K ∈ ℤ ∧ m ∈ ℤ ≥ M + K → m − K ∈ ℤ ≥ M
49 44 45 47 48 syl3anc ⊢ φ ∧ m ∈ W → m − K ∈ ℤ ≥ M
50 49 1 eleqtrrdi ⊢ φ ∧ m ∈ W → m − K ∈ Z
51 fveq2 ⊢ n = m − K → k ∈ Z ⟼ B ⁡ n = k ∈ Z ⟼ B ⁡ m − K
52 oveq2 ⊢ n = m − K → K + n = K + m - K
53 52 fveq2d ⊢ n = m − K → j ∈ W ⟼ A ⁡ K + n = j ∈ W ⟼ A ⁡ K + m - K
54 51 53 eqeq12d ⊢ n = m − K → k ∈ Z ⟼ B ⁡ n = j ∈ W ⟼ A ⁡ K + n ↔ k ∈ Z ⟼ B ⁡ m − K = j ∈ W ⟼ A ⁡ K + m - K
55 54 rspccva ⊢ ∀ n ∈ Z k ∈ Z ⟼ B ⁡ n = j ∈ W ⟼ A ⁡ K + n ∧ m − K ∈ Z → k ∈ Z ⟼ B ⁡ m − K = j ∈ W ⟼ A ⁡ K + m - K
56 43 50 55 syl2an2r ⊢ φ ∧ m ∈ W → k ∈ Z ⟼ B ⁡ m − K = j ∈ W ⟼ A ⁡ K + m - K
57 pncan3 ⊢ K ∈ ℂ ∧ m ∈ ℂ → K + m - K = m
58 9 11 57 syl2an ⊢ φ ∧ m ∈ W → K + m - K = m
59 58 fveq2d ⊢ φ ∧ m ∈ W → j ∈ W ⟼ A ⁡ K + m - K = j ∈ W ⟼ A ⁡ m
60 15 56 59 3eqtrrd ⊢ φ ∧ m ∈ W → j ∈ W ⟼ A ⁡ m = k ∈ Z ⟼ B shift K ⁡ m
61 8 60 sylan2br ⊢ φ ∧ m ∈ ℤ ≥ M + K → j ∈ W ⟼ A ⁡ m = k ∈ Z ⟼ B shift K ⁡ m
62 7 61 seqfeq ⊢ φ → seq M + K + j ∈ W ⟼ A = seq M + K + k ∈ Z ⟼ B shift K
63 62 breq1d ⊢ φ → seq M + K + j ∈ W ⟼ A ⇝ x ↔ seq M + K + k ∈ Z ⟼ B shift K ⇝ x
64 13 isershft ⊢ M ∈ ℤ ∧ K ∈ ℤ → seq M + k ∈ Z ⟼ B ⇝ x ↔ seq M + K + k ∈ Z ⟼ B shift K ⇝ x
65 5 4 64 syl2anc ⊢ φ → seq M + k ∈ Z ⟼ B ⇝ x ↔ seq M + K + k ∈ Z ⟼ B shift K ⇝ x
66 63 65 bitr4d ⊢ φ → seq M + K + j ∈ W ⟼ A ⇝ x ↔ seq M + k ∈ Z ⟼ B ⇝ x
67 66 iotabidv ⊢ φ → ι x | seq M + K + j ∈ W ⟼ A ⇝ x = ι x | seq M + k ∈ Z ⟼ B ⇝ x
68 df-fv ⊢ ⇝ ⁡ seq M + K + j ∈ W ⟼ A = ι x | seq M + K + j ∈ W ⟼ A ⇝ x
69 df-fv ⊢ ⇝ ⁡ seq M + k ∈ Z ⟼ B = ι x | seq M + k ∈ Z ⟼ B ⇝ x
70 67 68 69 3eqtr4g ⊢ φ → ⇝ ⁡ seq M + K + j ∈ W ⟼ A = ⇝ ⁡ seq M + k ∈ Z ⟼ B
71 eqidd ⊢ φ ∧ m ∈ W → j ∈ W ⟼ A ⁡ m = j ∈ W ⟼ A ⁡ m
72 6 fmpttd ⊢ φ → j ∈ W ⟼ A : W ⟶ ℂ
73 72 ffvelcdmda ⊢ φ ∧ m ∈ W → j ∈ W ⟼ A ⁡ m ∈ ℂ
74 2 7 71 73 isum ⊢ φ → ∑ m ∈ W j ∈ W ⟼ A ⁡ m = ⇝ ⁡ seq M + K + j ∈ W ⟼ A
75 eqidd ⊢ φ ∧ n ∈ Z → k ∈ Z ⟼ B ⁡ n = k ∈ Z ⟼ B ⁡ n
76 29 ralrimiva ⊢ φ → ∀ k ∈ Z K + k ∈ W
77 38 eleq1d ⊢ k = n → K + k ∈ W ↔ K + n ∈ W
78 77 rspccva ⊢ ∀ k ∈ Z K + k ∈ W ∧ n ∈ Z → K + n ∈ W
79 76 78 sylan ⊢ φ ∧ n ∈ Z → K + n ∈ W
80 ffvelcdm ⊢ j ∈ W ⟼ A : W ⟶ ℂ ∧ K + n ∈ W → j ∈ W ⟼ A ⁡ K + n ∈ ℂ
81 72 79 80 syl2an2r ⊢ φ ∧ n ∈ Z → j ∈ W ⟼ A ⁡ K + n ∈ ℂ
82 42 81 eqeltrd ⊢ φ ∧ n ∈ Z → k ∈ Z ⟼ B ⁡ n ∈ ℂ
83 1 5 75 82 isum ⊢ φ → ∑ n ∈ Z k ∈ Z ⟼ B ⁡ n = ⇝ ⁡ seq M + k ∈ Z ⟼ B
84 70 74 83 3eqtr4d ⊢ φ → ∑ m ∈ W j ∈ W ⟼ A ⁡ m = ∑ n ∈ Z k ∈ Z ⟼ B ⁡ n
85 sumfc ⊢ ∑ m ∈ W j ∈ W ⟼ A ⁡ m = ∑ j ∈ W A
86 sumfc ⊢ ∑ n ∈ Z k ∈ Z ⟼ B ⁡ n = ∑ k ∈ Z B
87 84 85 86 3eqtr3g ⊢ φ → ∑ j ∈ W A = ∑ k ∈ Z B