Metamath Proof Explorer


Theorem zsum

Description: Series sum with index set a subset of the upper integers. (Contributed by Mario Carneiro, 13-Jun-2019)

Ref Expression
Hypotheses zsum.1 𝑍 = ( ℤ𝑀 )
zsum.2 ( 𝜑𝑀 ∈ ℤ )
zsum.3 ( 𝜑𝐴𝑍 )
zsum.4 ( ( 𝜑𝑘𝑍 ) → ( 𝐹𝑘 ) = if ( 𝑘𝐴 , 𝐵 , 0 ) )
zsum.5 ( ( 𝜑𝑘𝐴 ) → 𝐵 ∈ ℂ )
Assertion zsum ( 𝜑 → Σ 𝑘𝐴 𝐵 = ( ⇝ ‘ seq 𝑀 ( + , 𝐹 ) ) )

Proof

Step Hyp Ref Expression
1 zsum.1 𝑍 = ( ℤ𝑀 )
2 zsum.2 ( 𝜑𝑀 ∈ ℤ )
3 zsum.3 ( 𝜑𝐴𝑍 )
4 zsum.4 ( ( 𝜑𝑘𝑍 ) → ( 𝐹𝑘 ) = if ( 𝑘𝐴 , 𝐵 , 0 ) )
5 zsum.5 ( ( 𝜑𝑘𝐴 ) → 𝐵 ∈ ℂ )
6 eleq1w ( 𝑛 = 𝑖 → ( 𝑛𝐴𝑖𝐴 ) )
7 csbeq1 ( 𝑛 = 𝑖 𝑛 / 𝑘 𝐵 = 𝑖 / 𝑘 𝐵 )
8 6 7 ifbieq1d ( 𝑛 = 𝑖 → if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) = if ( 𝑖𝐴 , 𝑖 / 𝑘 𝐵 , 0 ) )
9 8 cbvmptv ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) = ( 𝑖 ∈ ℤ ↦ if ( 𝑖𝐴 , 𝑖 / 𝑘 𝐵 , 0 ) )
10 simpll ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) → 𝜑 )
11 5 ralrimiva ( 𝜑 → ∀ 𝑘𝐴 𝐵 ∈ ℂ )
12 nfcsb1v 𝑘 𝑖 / 𝑘 𝐵
13 12 nfel1 𝑘 𝑖 / 𝑘 𝐵 ∈ ℂ
14 csbeq1a ( 𝑘 = 𝑖𝐵 = 𝑖 / 𝑘 𝐵 )
15 14 eleq1d ( 𝑘 = 𝑖 → ( 𝐵 ∈ ℂ ↔ 𝑖 / 𝑘 𝐵 ∈ ℂ ) )
16 13 15 rspc ( 𝑖𝐴 → ( ∀ 𝑘𝐴 𝐵 ∈ ℂ → 𝑖 / 𝑘 𝐵 ∈ ℂ ) )
17 11 16 syl5 ( 𝑖𝐴 → ( 𝜑 𝑖 / 𝑘 𝐵 ∈ ℂ ) )
18 10 17 mpan9 ( ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) ∧ 𝑖𝐴 ) → 𝑖 / 𝑘 𝐵 ∈ ℂ )
19 simplr ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) → 𝑚 ∈ ℤ )
20 2 ad2antrr ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) → 𝑀 ∈ ℤ )
21 simpr ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) → 𝐴 ⊆ ( ℤ𝑚 ) )
22 3 1 sseqtrdi ( 𝜑𝐴 ⊆ ( ℤ𝑀 ) )
23 22 ad2antrr ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) → 𝐴 ⊆ ( ℤ𝑀 ) )
24 9 18 19 20 21 23 sumrb ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) → ( seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ↔ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
25 24 biimpd ( ( ( 𝜑𝑚 ∈ ℤ ) ∧ 𝐴 ⊆ ( ℤ𝑚 ) ) → ( seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
26 25 expimpd ( ( 𝜑𝑚 ∈ ℤ ) → ( ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
27 26 rexlimdva ( 𝜑 → ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
28 3 ad2antrr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → 𝐴𝑍 )
29 uzssz ( ℤ𝑀 ) ⊆ ℤ
30 1 29 eqsstri 𝑍 ⊆ ℤ
31 zssre ℤ ⊆ ℝ
32 30 31 sstri 𝑍 ⊆ ℝ
33 ltso < Or ℝ
34 soss ( 𝑍 ⊆ ℝ → ( < Or ℝ → < Or 𝑍 ) )
35 32 33 34 mp2 < Or 𝑍
36 soss ( 𝐴𝑍 → ( < Or 𝑍 → < Or 𝐴 ) )
37 28 35 36 mpisyl ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → < Or 𝐴 )
38 fzfi ( 1 ... 𝑚 ) ∈ Fin
39 ovex ( 1 ... 𝑚 ) ∈ V
40 39 f1oen ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 → ( 1 ... 𝑚 ) ≈ 𝐴 )
41 40 adantl ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → ( 1 ... 𝑚 ) ≈ 𝐴 )
42 41 ensymd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → 𝐴 ≈ ( 1 ... 𝑚 ) )
43 enfii ( ( ( 1 ... 𝑚 ) ∈ Fin ∧ 𝐴 ≈ ( 1 ... 𝑚 ) ) → 𝐴 ∈ Fin )
44 38 42 43 sylancr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → 𝐴 ∈ Fin )
45 fz1iso ( ( < Or 𝐴𝐴 ∈ Fin ) → ∃ 𝑔 𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) )
46 37 44 45 syl2anc ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → ∃ 𝑔 𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) )
47 simpll ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) → 𝜑 )
48 47 17 mpan9 ( ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) ∧ 𝑖𝐴 ) → 𝑖 / 𝑘 𝐵 ∈ ℂ )
49 fveq2 ( 𝑛 = 𝑗 → ( 𝑓𝑛 ) = ( 𝑓𝑗 ) )
50 49 csbeq1d ( 𝑛 = 𝑗 ( 𝑓𝑛 ) / 𝑘 𝐵 = ( 𝑓𝑗 ) / 𝑘 𝐵 )
51 csbcow ( 𝑓𝑗 ) / 𝑖 𝑖 / 𝑘 𝐵 = ( 𝑓𝑗 ) / 𝑘 𝐵
52 50 51 eqtr4di ( 𝑛 = 𝑗 ( 𝑓𝑛 ) / 𝑘 𝐵 = ( 𝑓𝑗 ) / 𝑖 𝑖 / 𝑘 𝐵 )
53 52 cbvmptv ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) = ( 𝑗 ∈ ℕ ↦ ( 𝑓𝑗 ) / 𝑖 𝑖 / 𝑘 𝐵 )
54 eqid ( 𝑗 ∈ ℕ ↦ ( 𝑔𝑗 ) / 𝑖 𝑖 / 𝑘 𝐵 ) = ( 𝑗 ∈ ℕ ↦ ( 𝑔𝑗 ) / 𝑖 𝑖 / 𝑘 𝐵 )
55 simplr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) → 𝑚 ∈ ℕ )
56 2 ad2antrr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) → 𝑀 ∈ ℤ )
57 22 ad2antrr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) → 𝐴 ⊆ ( ℤ𝑀 ) )
58 simprl ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) → 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 )
59 simprr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) → 𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) )
60 9 48 53 54 55 56 57 58 59 summolem2a ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) ) ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) )
61 60 expr ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → ( 𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) )
62 61 exlimdv ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → ( ∃ 𝑔 𝑔 Isom < , < ( ( 1 ... ( ♯ ‘ 𝐴 ) ) , 𝐴 ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) )
63 46 62 mpd ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) )
64 breq2 ( 𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) → ( seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ↔ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) )
65 63 64 syl5ibrcom ( ( ( 𝜑𝑚 ∈ ℕ ) ∧ 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴 ) → ( 𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
66 65 expimpd ( ( 𝜑𝑚 ∈ ℕ ) → ( ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
67 66 exlimdv ( ( 𝜑𝑚 ∈ ℕ ) → ( ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
68 67 rexlimdva ( 𝜑 → ( ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
69 27 68 jaod ( 𝜑 → ( ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ∨ ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
70 2 adantr ( ( 𝜑 ∧ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) → 𝑀 ∈ ℤ )
71 22 adantr ( ( 𝜑 ∧ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) → 𝐴 ⊆ ( ℤ𝑀 ) )
72 simpr ( ( 𝜑 ∧ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 )
73 fveq2 ( 𝑚 = 𝑀 → ( ℤ𝑚 ) = ( ℤ𝑀 ) )
74 73 sseq2d ( 𝑚 = 𝑀 → ( 𝐴 ⊆ ( ℤ𝑚 ) ↔ 𝐴 ⊆ ( ℤ𝑀 ) ) )
75 seqeq1 ( 𝑚 = 𝑀 → seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) = seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) )
76 75 breq1d ( 𝑚 = 𝑀 → ( seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ↔ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
77 74 76 anbi12d ( 𝑚 = 𝑀 → ( ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ↔ ( 𝐴 ⊆ ( ℤ𝑀 ) ∧ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ) )
78 77 rspcev ( ( 𝑀 ∈ ℤ ∧ ( 𝐴 ⊆ ( ℤ𝑀 ) ∧ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ) → ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
79 70 71 72 78 syl12anc ( ( 𝜑 ∧ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) → ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
80 79 orcd ( ( 𝜑 ∧ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) → ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ∨ ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) ) )
81 80 ex ( 𝜑 → ( seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 → ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ∨ ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) ) ) )
82 69 81 impbid ( 𝜑 → ( ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ∨ ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) ) ↔ seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) )
83 simpr ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → 𝑗 ∈ ( ℤ𝑀 ) )
84 29 83 sselid ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → 𝑗 ∈ ℤ )
85 83 1 eleqtrrdi ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → 𝑗𝑍 )
86 4 ralrimiva ( 𝜑 → ∀ 𝑘𝑍 ( 𝐹𝑘 ) = if ( 𝑘𝐴 , 𝐵 , 0 ) )
87 86 adantr ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → ∀ 𝑘𝑍 ( 𝐹𝑘 ) = if ( 𝑘𝐴 , 𝐵 , 0 ) )
88 nfcsb1v 𝑘 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 )
89 88 nfeq2 𝑘 ( 𝐹𝑗 ) = 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 )
90 fveq2 ( 𝑘 = 𝑗 → ( 𝐹𝑘 ) = ( 𝐹𝑗 ) )
91 csbeq1a ( 𝑘 = 𝑗 → if ( 𝑘𝐴 , 𝐵 , 0 ) = 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) )
92 90 91 eqeq12d ( 𝑘 = 𝑗 → ( ( 𝐹𝑘 ) = if ( 𝑘𝐴 , 𝐵 , 0 ) ↔ ( 𝐹𝑗 ) = 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) ) )
93 89 92 rspc ( 𝑗𝑍 → ( ∀ 𝑘𝑍 ( 𝐹𝑘 ) = if ( 𝑘𝐴 , 𝐵 , 0 ) → ( 𝐹𝑗 ) = 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) ) )
94 85 87 93 sylc ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → ( 𝐹𝑗 ) = 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) )
95 fvex ( 𝐹𝑗 ) ∈ V
96 94 95 eqeltrrdi ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) ∈ V )
97 nfcv 𝑛 if ( 𝑘𝐴 , 𝐵 , 0 )
98 nfv 𝑘 𝑛𝐴
99 nfcsb1v 𝑘 𝑛 / 𝑘 𝐵
100 nfcv 𝑘 0
101 98 99 100 nfif 𝑘 if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 )
102 eleq1w ( 𝑘 = 𝑛 → ( 𝑘𝐴𝑛𝐴 ) )
103 csbeq1a ( 𝑘 = 𝑛𝐵 = 𝑛 / 𝑘 𝐵 )
104 102 103 ifbieq1d ( 𝑘 = 𝑛 → if ( 𝑘𝐴 , 𝐵 , 0 ) = if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) )
105 97 101 104 cbvmpt ( 𝑘 ∈ ℤ ↦ if ( 𝑘𝐴 , 𝐵 , 0 ) ) = ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) )
106 105 eqcomi ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) = ( 𝑘 ∈ ℤ ↦ if ( 𝑘𝐴 , 𝐵 , 0 ) )
107 106 fvmpts ( ( 𝑗 ∈ ℤ ∧ 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) ∈ V ) → ( ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ‘ 𝑗 ) = 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) )
108 84 96 107 syl2anc ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → ( ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ‘ 𝑗 ) = 𝑗 / 𝑘 if ( 𝑘𝐴 , 𝐵 , 0 ) )
109 108 94 eqtr4d ( ( 𝜑𝑗 ∈ ( ℤ𝑀 ) ) → ( ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ‘ 𝑗 ) = ( 𝐹𝑗 ) )
110 2 109 seqfeq ( 𝜑 → seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) = seq 𝑀 ( + , 𝐹 ) )
111 110 breq1d ( 𝜑 → ( seq 𝑀 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ↔ seq 𝑀 ( + , 𝐹 ) ⇝ 𝑥 ) )
112 82 111 bitrd ( 𝜑 → ( ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ∨ ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) ) ↔ seq 𝑀 ( + , 𝐹 ) ⇝ 𝑥 ) )
113 112 iotabidv ( 𝜑 → ( ℩ 𝑥 ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ∨ ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) ) ) = ( ℩ 𝑥 seq 𝑀 ( + , 𝐹 ) ⇝ 𝑥 ) )
114 df-sum Σ 𝑘𝐴 𝐵 = ( ℩ 𝑥 ( ∃ 𝑚 ∈ ℤ ( 𝐴 ⊆ ( ℤ𝑚 ) ∧ seq 𝑚 ( + , ( 𝑛 ∈ ℤ ↦ if ( 𝑛𝐴 , 𝑛 / 𝑘 𝐵 , 0 ) ) ) ⇝ 𝑥 ) ∨ ∃ 𝑚 ∈ ℕ ∃ 𝑓 ( 𝑓 : ( 1 ... 𝑚 ) –1-1-onto𝐴𝑥 = ( seq 1 ( + , ( 𝑛 ∈ ℕ ↦ ( 𝑓𝑛 ) / 𝑘 𝐵 ) ) ‘ 𝑚 ) ) ) )
115 df-fv ( ⇝ ‘ seq 𝑀 ( + , 𝐹 ) ) = ( ℩ 𝑥 seq 𝑀 ( + , 𝐹 ) ⇝ 𝑥 )
116 113 114 115 3eqtr4g ( 𝜑 → Σ 𝑘𝐴 𝐵 = ( ⇝ ‘ seq 𝑀 ( + , 𝐹 ) ) )