Metamath Proof Explorer


Theorem gsumpropd2lem

Description: Lemma for gsumpropd2 . (Contributed by Thierry Arnoux, 28-Jun-2017)

Ref Expression
Hypotheses gsumpropd2.f ⊢ φ → F ∈ V
gsumpropd2.g ⊢ φ → G ∈ W
gsumpropd2.h ⊢ φ → H ∈ X
gsumpropd2.b ⊢ φ → Base G = Base H
gsumpropd2.c ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → s + G t ∈ Base G
gsumpropd2.e ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → s + G t = s + H t
gsumpropd2.n ⊢ φ → Fun ⁡ F
gsumpropd2.r ⊢ φ → ran ⁡ F ⊆ Base G
gsumprop2dlem.1 ⊢ A = F -1 V ∖ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t
gsumprop2dlem.2 ⊢ B = F -1 V ∖ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
Assertion gsumpropd2lem ⊢ φ → ∑ G F = ∑ H F

Proof

Step Hyp Ref Expression
1 gsumpropd2.f ⊢ φ → F ∈ V
2 gsumpropd2.g ⊢ φ → G ∈ W
3 gsumpropd2.h ⊢ φ → H ∈ X
4 gsumpropd2.b ⊢ φ → Base G = Base H
5 gsumpropd2.c ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → s + G t ∈ Base G
6 gsumpropd2.e ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → s + G t = s + H t
7 gsumpropd2.n ⊢ φ → Fun ⁡ F
8 gsumpropd2.r ⊢ φ → ran ⁡ F ⊆ Base G
9 gsumprop2dlem.1 ⊢ A = F -1 V ∖ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t
10 gsumprop2dlem.2 ⊢ B = F -1 V ∖ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
11 4 adantr ⊢ φ ∧ s ∈ Base G → Base G = Base H
12 6 eqeq1d ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → s + G t = t ↔ s + H t = t
13 6 oveqrspc2v ⊢ φ ∧ a ∈ Base G ∧ b ∈ Base G → a + G b = a + H b
14 13 oveqrspc2v ⊢ φ ∧ t ∈ Base G ∧ s ∈ Base G → t + G s = t + H s
15 14 ancom2s ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → t + G s = t + H s
16 15 eqeq1d ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → t + G s = t ↔ t + H s = t
17 12 16 anbi12d ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → s + G t = t ∧ t + G s = t ↔ s + H t = t ∧ t + H s = t
18 17 anassrs ⊢ φ ∧ s ∈ Base G ∧ t ∈ Base G → s + G t = t ∧ t + G s = t ↔ s + H t = t ∧ t + H s = t
19 11 18 raleqbidva ⊢ φ ∧ s ∈ Base G → ∀ t ∈ Base G s + G t = t ∧ t + G s = t ↔ ∀ t ∈ Base H s + H t = t ∧ t + H s = t
20 4 19 rabeqbidva ⊢ φ → s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t = s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
21 20 sseq2d ⊢ φ → ran ⁡ F ⊆ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t ↔ ran ⁡ F ⊆ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
22 eqidd ⊢ φ → Base G = Base G
23 22 4 6 grpidpropd ⊢ φ → 0 G = 0 H
24 simprl ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n → n ∈ ℤ ≥ m
25 8 ad2antrr ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ m … n → ran ⁡ F ⊆ Base G
26 7 ad2antrr ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ m … n → Fun ⁡ F
27 simpr ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ m … n → s ∈ m … n
28 simplrr ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ m … n → dom ⁡ F = m … n
29 27 28 eleqtrrd ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ m … n → s ∈ dom ⁡ F
30 fvelrn ⊢ Fun ⁡ F ∧ s ∈ dom ⁡ F → F ⁡ s ∈ ran ⁡ F
31 26 29 30 syl2anc ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ m … n → F ⁡ s ∈ ran ⁡ F
32 25 31 sseldd ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ m … n → F ⁡ s ∈ Base G
33 5 adantlr ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ Base G ∧ t ∈ Base G → s + G t ∈ Base G
34 6 adantlr ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n ∧ s ∈ Base G ∧ t ∈ Base G → s + G t = s + H t
35 24 32 33 34 seqfeq4 ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n → seq m + G F ⁡ n = seq m + H F ⁡ n
36 35 eqeq2d ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n → x = seq m + G F ⁡ n ↔ x = seq m + H F ⁡ n
37 36 anassrs ⊢ φ ∧ n ∈ ℤ ≥ m ∧ dom ⁡ F = m … n → x = seq m + G F ⁡ n ↔ x = seq m + H F ⁡ n
38 37 pm5.32da ⊢ φ ∧ n ∈ ℤ ≥ m → dom ⁡ F = m … n ∧ x = seq m + G F ⁡ n ↔ dom ⁡ F = m … n ∧ x = seq m + H F ⁡ n
39 38 rexbidva ⊢ φ → ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + G F ⁡ n ↔ ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + H F ⁡ n
40 39 exbidv ⊢ φ → ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + G F ⁡ n ↔ ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + H F ⁡ n
41 40 iotabidv ⊢ φ → ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + G F ⁡ n = ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + H F ⁡ n
42 20 difeq2d ⊢ φ → V ∖ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t = V ∖ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
43 42 imaeq2d ⊢ φ → F -1 V ∖ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t = F -1 V ∖ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
44 43 9 10 3eqtr4g ⊢ φ → A = B
45 44 fveq2d ⊢ φ → A = B
46 45 fveq2d ⊢ φ → seq 1 + G F ∘ f ⁡ A = seq 1 + G F ∘ f ⁡ B
47 46 adantr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A → seq 1 + G F ∘ f ⁡ A = seq 1 + G F ∘ f ⁡ B
48 simpr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 → B ∈ ℤ ≥ 1
49 8 ad3antrrr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → ran ⁡ F ⊆ Base G
50 f1ofun ⊢ f : 1 … A ⟶ 1-1 onto A → Fun ⁡ f
51 50 ad3antlr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → Fun ⁡ f
52 simpr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → a ∈ 1 … B
53 f1odm ⊢ f : 1 … A ⟶ 1-1 onto A → dom ⁡ f = 1 … A
54 53 ad3antlr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → dom ⁡ f = 1 … A
55 45 oveq2d ⊢ φ → 1 … A = 1 … B
56 55 ad3antrrr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → 1 … A = 1 … B
57 54 56 eqtrd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → dom ⁡ f = 1 … B
58 52 57 eleqtrrd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → a ∈ dom ⁡ f
59 fvco ⊢ Fun ⁡ f ∧ a ∈ dom ⁡ f → F ∘ f ⁡ a = F ⁡ f ⁡ a
60 51 58 59 syl2anc ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → F ∘ f ⁡ a = F ⁡ f ⁡ a
61 7 ad3antrrr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → Fun ⁡ F
62 difpreima ⊢ Fun ⁡ F → F -1 V ∖ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t = F -1 V ∖ F -1 s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t
63 7 62 syl ⊢ φ → F -1 V ∖ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t = F -1 V ∖ F -1 s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t
64 9 63 eqtrid ⊢ φ → A = F -1 V ∖ F -1 s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t
65 difss ⊢ F -1 V ∖ F -1 s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t ⊆ F -1 V
66 64 65 eqsstrdi ⊢ φ → A ⊆ F -1 V
67 dfdm4 ⊢ dom ⁡ F = ran ⁡ F -1
68 dfrn4 ⊢ ran ⁡ F -1 = F -1 V
69 67 68 eqtri ⊢ dom ⁡ F = F -1 V
70 66 69 sseqtrrdi ⊢ φ → A ⊆ dom ⁡ F
71 70 ad3antrrr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → A ⊆ dom ⁡ F
72 f1of ⊢ f : 1 … A ⟶ 1-1 onto A → f : 1 … A ⟶ A
73 72 ad3antlr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → f : 1 … A ⟶ A
74 52 56 eleqtrrd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → a ∈ 1 … A
75 73 74 ffvelcdmd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → f ⁡ a ∈ A
76 71 75 sseldd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → f ⁡ a ∈ dom ⁡ F
77 fvelrn ⊢ Fun ⁡ F ∧ f ⁡ a ∈ dom ⁡ F → F ⁡ f ⁡ a ∈ ran ⁡ F
78 61 76 77 syl2anc ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → F ⁡ f ⁡ a ∈ ran ⁡ F
79 60 78 eqeltrd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → F ∘ f ⁡ a ∈ ran ⁡ F
80 49 79 sseldd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ 1 … B → F ∘ f ⁡ a ∈ Base G
81 5 caovclg ⊢ φ ∧ a ∈ Base G ∧ b ∈ Base G → a + G b ∈ Base G
82 81 ad4ant14 ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ Base G ∧ b ∈ Base G → a + G b ∈ Base G
83 13 ad4ant14 ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 ∧ a ∈ Base G ∧ b ∈ Base G → a + G b = a + H b
84 48 80 82 83 seqfeq4 ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ B ∈ ℤ ≥ 1 → seq 1 + G F ∘ f ⁡ B = seq 1 + H F ∘ f ⁡ B
85 simpr ⊢ φ ∧ ¬ B ∈ ℤ ≥ 1 → ¬ B ∈ ℤ ≥ 1
86 1z ⊢ 1 ∈ ℤ
87 seqfn ⊢ 1 ∈ ℤ → seq 1 + G F ∘ f Fn ℤ ≥ 1
88 fndm ⊢ seq 1 + G F ∘ f Fn ℤ ≥ 1 → dom ⁡ seq 1 + G F ∘ f = ℤ ≥ 1
89 86 87 88 mp2b ⊢ dom ⁡ seq 1 + G F ∘ f = ℤ ≥ 1
90 89 eleq2i ⊢ B ∈ dom ⁡ seq 1 + G F ∘ f ↔ B ∈ ℤ ≥ 1
91 85 90 sylnibr ⊢ φ ∧ ¬ B ∈ ℤ ≥ 1 → ¬ B ∈ dom ⁡ seq 1 + G F ∘ f
92 ndmfv ⊢ ¬ B ∈ dom ⁡ seq 1 + G F ∘ f → seq 1 + G F ∘ f ⁡ B = ∅
93 91 92 syl ⊢ φ ∧ ¬ B ∈ ℤ ≥ 1 → seq 1 + G F ∘ f ⁡ B = ∅
94 seqfn ⊢ 1 ∈ ℤ → seq 1 + H F ∘ f Fn ℤ ≥ 1
95 fndm ⊢ seq 1 + H F ∘ f Fn ℤ ≥ 1 → dom ⁡ seq 1 + H F ∘ f = ℤ ≥ 1
96 86 94 95 mp2b ⊢ dom ⁡ seq 1 + H F ∘ f = ℤ ≥ 1
97 96 eleq2i ⊢ B ∈ dom ⁡ seq 1 + H F ∘ f ↔ B ∈ ℤ ≥ 1
98 85 97 sylnibr ⊢ φ ∧ ¬ B ∈ ℤ ≥ 1 → ¬ B ∈ dom ⁡ seq 1 + H F ∘ f
99 ndmfv ⊢ ¬ B ∈ dom ⁡ seq 1 + H F ∘ f → seq 1 + H F ∘ f ⁡ B = ∅
100 98 99 syl ⊢ φ ∧ ¬ B ∈ ℤ ≥ 1 → seq 1 + H F ∘ f ⁡ B = ∅
101 93 100 eqtr4d ⊢ φ ∧ ¬ B ∈ ℤ ≥ 1 → seq 1 + G F ∘ f ⁡ B = seq 1 + H F ∘ f ⁡ B
102 101 adantlr ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A ∧ ¬ B ∈ ℤ ≥ 1 → seq 1 + G F ∘ f ⁡ B = seq 1 + H F ∘ f ⁡ B
103 84 102 pm2.61dan ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A → seq 1 + G F ∘ f ⁡ B = seq 1 + H F ∘ f ⁡ B
104 47 103 eqtrd ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A → seq 1 + G F ∘ f ⁡ A = seq 1 + H F ∘ f ⁡ B
105 104 eqeq2d ⊢ φ ∧ f : 1 … A ⟶ 1-1 onto A → x = seq 1 + G F ∘ f ⁡ A ↔ x = seq 1 + H F ∘ f ⁡ B
106 105 pm5.32da ⊢ φ → f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + G F ∘ f ⁡ A ↔ f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + H F ∘ f ⁡ B
107 55 f1oeq2d ⊢ φ → f : 1 … A ⟶ 1-1 onto A ↔ f : 1 … B ⟶ 1-1 onto A
108 44 f1oeq3d ⊢ φ → f : 1 … B ⟶ 1-1 onto A ↔ f : 1 … B ⟶ 1-1 onto B
109 107 108 bitrd ⊢ φ → f : 1 … A ⟶ 1-1 onto A ↔ f : 1 … B ⟶ 1-1 onto B
110 109 anbi1d ⊢ φ → f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + H F ∘ f ⁡ B ↔ f : 1 … B ⟶ 1-1 onto B ∧ x = seq 1 + H F ∘ f ⁡ B
111 106 110 bitrd ⊢ φ → f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + G F ∘ f ⁡ A ↔ f : 1 … B ⟶ 1-1 onto B ∧ x = seq 1 + H F ∘ f ⁡ B
112 111 exbidv ⊢ φ → ∃ f f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + G F ∘ f ⁡ A ↔ ∃ f f : 1 … B ⟶ 1-1 onto B ∧ x = seq 1 + H F ∘ f ⁡ B
113 112 iotabidv ⊢ φ → ι x | ∃ f f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + G F ∘ f ⁡ A = ι x | ∃ f f : 1 … B ⟶ 1-1 onto B ∧ x = seq 1 + H F ∘ f ⁡ B
114 41 113 ifeq12d ⊢ φ → if dom ⁡ F ∈ ran ⁡ … ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + G F ⁡ n ι x | ∃ f f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + G F ∘ f ⁡ A = if dom ⁡ F ∈ ran ⁡ … ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + H F ⁡ n ι x | ∃ f f : 1 … B ⟶ 1-1 onto B ∧ x = seq 1 + H F ∘ f ⁡ B
115 21 23 114 ifbieq12d ⊢ φ → if ran ⁡ F ⊆ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t 0 G if dom ⁡ F ∈ ran ⁡ … ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + G F ⁡ n ι x | ∃ f f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + G F ∘ f ⁡ A = if ran ⁡ F ⊆ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t 0 H if dom ⁡ F ∈ ran ⁡ … ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + H F ⁡ n ι x | ∃ f f : 1 … B ⟶ 1-1 onto B ∧ x = seq 1 + H F ∘ f ⁡ B
116 eqid ⊢ Base G = Base G
117 eqid ⊢ 0 G = 0 G
118 eqid ⊢ + G = + G
119 eqid ⊢ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t = s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t
120 9 a1i ⊢ φ → A = F -1 V ∖ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t
121 eqidd ⊢ φ → dom ⁡ F = dom ⁡ F
122 116 117 118 119 120 2 1 121 gsumvalx ⊢ φ → ∑ G F = if ran ⁡ F ⊆ s ∈ Base G | ∀ t ∈ Base G s + G t = t ∧ t + G s = t 0 G if dom ⁡ F ∈ ran ⁡ … ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + G F ⁡ n ι x | ∃ f f : 1 … A ⟶ 1-1 onto A ∧ x = seq 1 + G F ∘ f ⁡ A
123 eqid ⊢ Base H = Base H
124 eqid ⊢ 0 H = 0 H
125 eqid ⊢ + H = + H
126 eqid ⊢ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t = s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
127 10 a1i ⊢ φ → B = F -1 V ∖ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t
128 123 124 125 126 127 3 1 121 gsumvalx ⊢ φ → ∑ H F = if ran ⁡ F ⊆ s ∈ Base H | ∀ t ∈ Base H s + H t = t ∧ t + H s = t 0 H if dom ⁡ F ∈ ran ⁡ … ι x | ∃ m ∃ n ∈ ℤ ≥ m dom ⁡ F = m … n ∧ x = seq m + H F ⁡ n ι x | ∃ f f : 1 … B ⟶ 1-1 onto B ∧ x = seq 1 + H F ∘ f ⁡ B
129 115 122 128 3eqtr4d ⊢ φ → ∑ G F = ∑ H F