Metamath Proof Explorer


Theorem climrlim2

Description: Produce a real limit from an integer limit, where the real function is only dependent on the integer part of x . (Contributed by Mario Carneiro, 2-May-2016)

Ref Expression
Hypotheses climrlim2.1 𝑍 = ( ℤ𝑀 )
climrlim2.2 ( 𝑛 = ( ⌊ ‘ 𝑥 ) → 𝐵 = 𝐶 )
climrlim2.3 ( 𝜑𝐴 ⊆ ℝ )
climrlim2.4 ( 𝜑𝑀 ∈ ℤ )
climrlim2.5 ( 𝜑 → ( 𝑛𝑍𝐵 ) ⇝ 𝐷 )
climrlim2.6 ( ( 𝜑𝑛𝑍 ) → 𝐵 ∈ ℂ )
climrlim2.7 ( ( 𝜑𝑥𝐴 ) → 𝑀𝑥 )
Assertion climrlim2 ( 𝜑 → ( 𝑥𝐴𝐶 ) ⇝𝑟 𝐷 )

Proof

Step Hyp Ref Expression
1 climrlim2.1 𝑍 = ( ℤ𝑀 )
2 climrlim2.2 ( 𝑛 = ( ⌊ ‘ 𝑥 ) → 𝐵 = 𝐶 )
3 climrlim2.3 ( 𝜑𝐴 ⊆ ℝ )
4 climrlim2.4 ( 𝜑𝑀 ∈ ℤ )
5 climrlim2.5 ( 𝜑 → ( 𝑛𝑍𝐵 ) ⇝ 𝐷 )
6 climrlim2.6 ( ( 𝜑𝑛𝑍 ) → 𝐵 ∈ ℂ )
7 climrlim2.7 ( ( 𝜑𝑥𝐴 ) → 𝑀𝑥 )
8 eluzelz ( 𝑗 ∈ ( ℤ𝑀 ) → 𝑗 ∈ ℤ )
9 8 1 eleq2s ( 𝑗𝑍𝑗 ∈ ℤ )
10 9 ad2antlr ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → 𝑗 ∈ ℤ )
11 3 sselda ( ( 𝜑𝑥𝐴 ) → 𝑥 ∈ ℝ )
12 11 flcld ( ( 𝜑𝑥𝐴 ) → ( ⌊ ‘ 𝑥 ) ∈ ℤ )
13 12 adantlr ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑥𝐴 ) → ( ⌊ ‘ 𝑥 ) ∈ ℤ )
14 13 ad2ant2r ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( ⌊ ‘ 𝑥 ) ∈ ℤ )
15 simprr ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → 𝑗𝑥 )
16 11 adantlr ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑥𝐴 ) → 𝑥 ∈ ℝ )
17 16 ad2ant2r ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → 𝑥 ∈ ℝ )
18 flge ( ( 𝑥 ∈ ℝ ∧ 𝑗 ∈ ℤ ) → ( 𝑗𝑥𝑗 ≤ ( ⌊ ‘ 𝑥 ) ) )
19 17 10 18 syl2anc ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( 𝑗𝑥𝑗 ≤ ( ⌊ ‘ 𝑥 ) ) )
20 15 19 mpbid ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → 𝑗 ≤ ( ⌊ ‘ 𝑥 ) )
21 eluz2 ( ( ⌊ ‘ 𝑥 ) ∈ ( ℤ𝑗 ) ↔ ( 𝑗 ∈ ℤ ∧ ( ⌊ ‘ 𝑥 ) ∈ ℤ ∧ 𝑗 ≤ ( ⌊ ‘ 𝑥 ) ) )
22 10 14 20 21 syl3anbrc ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( ⌊ ‘ 𝑥 ) ∈ ( ℤ𝑗 ) )
23 simpr ( ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 )
24 23 ralimi ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ∀ 𝑘 ∈ ( ℤ𝑗 ) ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 )
25 fveq2 ( 𝑘 = ( ⌊ ‘ 𝑥 ) → ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) = ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) )
26 25 fvoveq1d ( 𝑘 = ( ⌊ ‘ 𝑥 ) → ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) = ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) − 𝐷 ) ) )
27 26 breq1d ( 𝑘 = ( ⌊ ‘ 𝑥 ) → ( ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ↔ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) − 𝐷 ) ) < 𝑦 ) )
28 27 rspcv ( ( ⌊ ‘ 𝑥 ) ∈ ( ℤ𝑗 ) → ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 → ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) − 𝐷 ) ) < 𝑦 ) )
29 22 24 28 syl2im ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) − 𝐷 ) ) < 𝑦 ) )
30 eqid ( 𝑛𝑍𝐵 ) = ( 𝑛𝑍𝐵 )
31 4 adantr ( ( 𝜑𝑥𝐴 ) → 𝑀 ∈ ℤ )
32 flge ( ( 𝑥 ∈ ℝ ∧ 𝑀 ∈ ℤ ) → ( 𝑀𝑥𝑀 ≤ ( ⌊ ‘ 𝑥 ) ) )
33 11 31 32 syl2anc ( ( 𝜑𝑥𝐴 ) → ( 𝑀𝑥𝑀 ≤ ( ⌊ ‘ 𝑥 ) ) )
34 7 33 mpbid ( ( 𝜑𝑥𝐴 ) → 𝑀 ≤ ( ⌊ ‘ 𝑥 ) )
35 eluz2 ( ( ⌊ ‘ 𝑥 ) ∈ ( ℤ𝑀 ) ↔ ( 𝑀 ∈ ℤ ∧ ( ⌊ ‘ 𝑥 ) ∈ ℤ ∧ 𝑀 ≤ ( ⌊ ‘ 𝑥 ) ) )
36 31 12 34 35 syl3anbrc ( ( 𝜑𝑥𝐴 ) → ( ⌊ ‘ 𝑥 ) ∈ ( ℤ𝑀 ) )
37 36 1 eleqtrrdi ( ( 𝜑𝑥𝐴 ) → ( ⌊ ‘ 𝑥 ) ∈ 𝑍 )
38 2 eleq1d ( 𝑛 = ( ⌊ ‘ 𝑥 ) → ( 𝐵 ∈ ℂ ↔ 𝐶 ∈ ℂ ) )
39 6 ralrimiva ( 𝜑 → ∀ 𝑛𝑍 𝐵 ∈ ℂ )
40 39 adantr ( ( 𝜑𝑥𝐴 ) → ∀ 𝑛𝑍 𝐵 ∈ ℂ )
41 38 40 37 rspcdva ( ( 𝜑𝑥𝐴 ) → 𝐶 ∈ ℂ )
42 30 2 37 41 fvmptd3 ( ( 𝜑𝑥𝐴 ) → ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) = 𝐶 )
43 42 adantlr ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑥𝐴 ) → ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) = 𝐶 )
44 43 ad2ant2r ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) = 𝐶 )
45 44 fvoveq1d ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) − 𝐷 ) ) = ( abs ‘ ( 𝐶𝐷 ) ) )
46 45 breq1d ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ ( ⌊ ‘ 𝑥 ) ) − 𝐷 ) ) < 𝑦 ↔ ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) )
47 29 46 sylibd ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ ( 𝑥𝐴𝑗𝑥 ) ) → ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) )
48 47 expr ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ 𝑥𝐴 ) → ( 𝑗𝑥 → ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) )
49 48 com23 ( ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) ∧ 𝑥𝐴 ) → ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) )
50 49 ralrimdva ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) → ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ∀ 𝑥𝐴 ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) )
51 eluzelre ( 𝑗 ∈ ( ℤ𝑀 ) → 𝑗 ∈ ℝ )
52 51 1 eleq2s ( 𝑗𝑍𝑗 ∈ ℝ )
53 52 adantl ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) → 𝑗 ∈ ℝ )
54 50 53 jctild ( ( ( 𝜑𝑦 ∈ ℝ+ ) ∧ 𝑗𝑍 ) → ( ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ( 𝑗 ∈ ℝ ∧ ∀ 𝑥𝐴 ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) ) )
55 54 expimpd ( ( 𝜑𝑦 ∈ ℝ+ ) → ( ( 𝑗𝑍 ∧ ∀ 𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) ) → ( 𝑗 ∈ ℝ ∧ ∀ 𝑥𝐴 ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) ) )
56 55 reximdv2 ( ( 𝜑𝑦 ∈ ℝ+ ) → ( ∃ 𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ∃ 𝑗 ∈ ℝ ∀ 𝑥𝐴 ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) )
57 56 ralimdva ( 𝜑 → ( ∀ 𝑦 ∈ ℝ+𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) → ∀ 𝑦 ∈ ℝ+𝑗 ∈ ℝ ∀ 𝑥𝐴 ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) )
58 57 adantld ( 𝜑 → ( ( 𝐷 ∈ ℂ ∧ ∀ 𝑦 ∈ ℝ+𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) ) → ∀ 𝑦 ∈ ℝ+𝑗 ∈ ℝ ∀ 𝑥𝐴 ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) )
59 climrel Rel ⇝
60 59 brrelex1i ( ( 𝑛𝑍𝐵 ) ⇝ 𝐷 → ( 𝑛𝑍𝐵 ) ∈ V )
61 5 60 syl ( 𝜑 → ( 𝑛𝑍𝐵 ) ∈ V )
62 eqidd ( ( 𝜑𝑘𝑍 ) → ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) = ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) )
63 1 4 61 62 clim2 ( 𝜑 → ( ( 𝑛𝑍𝐵 ) ⇝ 𝐷 ↔ ( 𝐷 ∈ ℂ ∧ ∀ 𝑦 ∈ ℝ+𝑗𝑍𝑘 ∈ ( ℤ𝑗 ) ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) ∈ ℂ ∧ ( abs ‘ ( ( ( 𝑛𝑍𝐵 ) ‘ 𝑘 ) − 𝐷 ) ) < 𝑦 ) ) ) )
64 41 ralrimiva ( 𝜑 → ∀ 𝑥𝐴 𝐶 ∈ ℂ )
65 climcl ( ( 𝑛𝑍𝐵 ) ⇝ 𝐷𝐷 ∈ ℂ )
66 5 65 syl ( 𝜑𝐷 ∈ ℂ )
67 64 3 66 rlim2 ( 𝜑 → ( ( 𝑥𝐴𝐶 ) ⇝𝑟 𝐷 ↔ ∀ 𝑦 ∈ ℝ+𝑗 ∈ ℝ ∀ 𝑥𝐴 ( 𝑗𝑥 → ( abs ‘ ( 𝐶𝐷 ) ) < 𝑦 ) ) )
68 58 63 67 3imtr4d ( 𝜑 → ( ( 𝑛𝑍𝐵 ) ⇝ 𝐷 → ( 𝑥𝐴𝐶 ) ⇝𝑟 𝐷 ) )
69 5 68 mpd ( 𝜑 → ( 𝑥𝐴𝐶 ) ⇝𝑟 𝐷 )