Metamath Proof Explorer


Theorem isumrpcl

Description: The infinite sum of positive reals is positive. (Contributed by Paul Chapman, 9-Feb-2008) (Revised by Mario Carneiro, 24-Apr-2014)

Ref Expression
Hypotheses isumrpcl.1 𝑍 = ( ℤ𝑀 )
isumrpcl.2 𝑊 = ( ℤ𝑁 )
isumrpcl.3 ( 𝜑𝑁𝑍 )
isumrpcl.4 ( ( 𝜑𝑘𝑍 ) → ( 𝐹𝑘 ) = 𝐴 )
isumrpcl.5 ( ( 𝜑𝑘𝑍 ) → 𝐴 ∈ ℝ+ )
isumrpcl.6 ( 𝜑 → seq 𝑀 ( + , 𝐹 ) ∈ dom ⇝ )
Assertion isumrpcl ( 𝜑 → Σ 𝑘𝑊 𝐴 ∈ ℝ+ )

Proof

Step Hyp Ref Expression
1 isumrpcl.1 𝑍 = ( ℤ𝑀 )
2 isumrpcl.2 𝑊 = ( ℤ𝑁 )
3 isumrpcl.3 ( 𝜑𝑁𝑍 )
4 isumrpcl.4 ( ( 𝜑𝑘𝑍 ) → ( 𝐹𝑘 ) = 𝐴 )
5 isumrpcl.5 ( ( 𝜑𝑘𝑍 ) → 𝐴 ∈ ℝ+ )
6 isumrpcl.6 ( 𝜑 → seq 𝑀 ( + , 𝐹 ) ∈ dom ⇝ )
7 3 1 eleqtrdi ( 𝜑𝑁 ∈ ( ℤ𝑀 ) )
8 eluzelz ( 𝑁 ∈ ( ℤ𝑀 ) → 𝑁 ∈ ℤ )
9 7 8 syl ( 𝜑𝑁 ∈ ℤ )
10 uzss ( 𝑁 ∈ ( ℤ𝑀 ) → ( ℤ𝑁 ) ⊆ ( ℤ𝑀 ) )
11 7 10 syl ( 𝜑 → ( ℤ𝑁 ) ⊆ ( ℤ𝑀 ) )
12 11 2 1 3sstr4g ( 𝜑𝑊𝑍 )
13 12 sselda ( ( 𝜑𝑘𝑊 ) → 𝑘𝑍 )
14 13 4 syldan ( ( 𝜑𝑘𝑊 ) → ( 𝐹𝑘 ) = 𝐴 )
15 5 rpred ( ( 𝜑𝑘𝑍 ) → 𝐴 ∈ ℝ )
16 13 15 syldan ( ( 𝜑𝑘𝑊 ) → 𝐴 ∈ ℝ )
17 4 5 eqeltrd ( ( 𝜑𝑘𝑍 ) → ( 𝐹𝑘 ) ∈ ℝ+ )
18 17 rpcnd ( ( 𝜑𝑘𝑍 ) → ( 𝐹𝑘 ) ∈ ℂ )
19 1 3 18 iserex ( 𝜑 → ( seq 𝑀 ( + , 𝐹 ) ∈ dom ⇝ ↔ seq 𝑁 ( + , 𝐹 ) ∈ dom ⇝ ) )
20 6 19 mpbid ( 𝜑 → seq 𝑁 ( + , 𝐹 ) ∈ dom ⇝ )
21 2 9 14 16 20 isumrecl ( 𝜑 → Σ 𝑘𝑊 𝐴 ∈ ℝ )
22 fveq2 ( 𝑘 = 𝑁 → ( 𝐹𝑘 ) = ( 𝐹𝑁 ) )
23 22 eleq1d ( 𝑘 = 𝑁 → ( ( 𝐹𝑘 ) ∈ ℝ+ ↔ ( 𝐹𝑁 ) ∈ ℝ+ ) )
24 17 ralrimiva ( 𝜑 → ∀ 𝑘𝑍 ( 𝐹𝑘 ) ∈ ℝ+ )
25 23 24 3 rspcdva ( 𝜑 → ( 𝐹𝑁 ) ∈ ℝ+ )
26 seq1 ( 𝑁 ∈ ℤ → ( seq 𝑁 ( + , 𝐹 ) ‘ 𝑁 ) = ( 𝐹𝑁 ) )
27 9 26 syl ( 𝜑 → ( seq 𝑁 ( + , 𝐹 ) ‘ 𝑁 ) = ( 𝐹𝑁 ) )
28 uzid ( 𝑁 ∈ ℤ → 𝑁 ∈ ( ℤ𝑁 ) )
29 9 28 syl ( 𝜑𝑁 ∈ ( ℤ𝑁 ) )
30 29 2 eleqtrrdi ( 𝜑𝑁𝑊 )
31 16 recnd ( ( 𝜑𝑘𝑊 ) → 𝐴 ∈ ℂ )
32 2 9 14 31 20 isumclim2 ( 𝜑 → seq 𝑁 ( + , 𝐹 ) ⇝ Σ 𝑘𝑊 𝐴 )
33 12 sseld ( 𝜑 → ( 𝑚𝑊𝑚𝑍 ) )
34 fveq2 ( 𝑘 = 𝑚 → ( 𝐹𝑘 ) = ( 𝐹𝑚 ) )
35 34 eleq1d ( 𝑘 = 𝑚 → ( ( 𝐹𝑘 ) ∈ ℝ+ ↔ ( 𝐹𝑚 ) ∈ ℝ+ ) )
36 35 rspcv ( 𝑚𝑍 → ( ∀ 𝑘𝑍 ( 𝐹𝑘 ) ∈ ℝ+ → ( 𝐹𝑚 ) ∈ ℝ+ ) )
37 33 24 36 syl6ci ( 𝜑 → ( 𝑚𝑊 → ( 𝐹𝑚 ) ∈ ℝ+ ) )
38 37 imp ( ( 𝜑𝑚𝑊 ) → ( 𝐹𝑚 ) ∈ ℝ+ )
39 38 rpred ( ( 𝜑𝑚𝑊 ) → ( 𝐹𝑚 ) ∈ ℝ )
40 38 rpge0d ( ( 𝜑𝑚𝑊 ) → 0 ≤ ( 𝐹𝑚 ) )
41 2 30 32 39 40 climserle ( 𝜑 → ( seq 𝑁 ( + , 𝐹 ) ‘ 𝑁 ) ≤ Σ 𝑘𝑊 𝐴 )
42 27 41 eqbrtrrd ( 𝜑 → ( 𝐹𝑁 ) ≤ Σ 𝑘𝑊 𝐴 )
43 21 25 42 rpgecld ( 𝜑 → Σ 𝑘𝑊 𝐴 ∈ ℝ+ )