Metamath Proof Explorer


Theorem rfcnnnub

Description: Given a real continuous function F defined on a compact topological space, there is always a positive integer that is a strict upper bound of its range. (Contributed by Glauco Siliprandi, 20-Apr-2017)

Ref Expression
Hypotheses rfcnnnub.1 𝑡 𝐹
rfcnnnub.2 𝑡 𝜑
rfcnnnub.3 𝐾 = ( topGen ‘ ran (,) )
rfcnnnub.4 ( 𝜑𝐽 ∈ Comp )
rfcnnnub.5 𝑇 = 𝐽
rfcnnnub.6 ( 𝜑𝑇 ≠ ∅ )
rfcnnnub.7 𝐶 = ( 𝐽 Cn 𝐾 )
rfcnnnub.8 ( 𝜑𝐹𝐶 )
Assertion rfcnnnub ( 𝜑 → ∃ 𝑛 ∈ ℕ ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 )

Proof

Step Hyp Ref Expression
1 rfcnnnub.1 𝑡 𝐹
2 rfcnnnub.2 𝑡 𝜑
3 rfcnnnub.3 𝐾 = ( topGen ‘ ran (,) )
4 rfcnnnub.4 ( 𝜑𝐽 ∈ Comp )
5 rfcnnnub.5 𝑇 = 𝐽
6 rfcnnnub.6 ( 𝜑𝑇 ≠ ∅ )
7 rfcnnnub.7 𝐶 = ( 𝐽 Cn 𝐾 )
8 rfcnnnub.8 ( 𝜑𝐹𝐶 )
9 nfcv 𝑠 𝐹
10 nfcv 𝑠 𝑇
11 nfcv 𝑡 𝑇
12 nfv 𝑠 𝜑
13 8 7 eleqtrdi ( 𝜑𝐹 ∈ ( 𝐽 Cn 𝐾 ) )
14 9 1 10 11 12 2 5 3 4 13 6 evthf ( 𝜑 → ∃ 𝑠𝑇𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) )
15 df-rex ( ∃ 𝑠𝑇𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ↔ ∃ 𝑠 ( 𝑠𝑇 ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) )
16 14 15 sylib ( 𝜑 → ∃ 𝑠 ( 𝑠𝑇 ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) )
17 3 5 7 8 fcnre ( 𝜑𝐹 : 𝑇 ⟶ ℝ )
18 17 ffvelrnda ( ( 𝜑𝑠𝑇 ) → ( 𝐹𝑠 ) ∈ ℝ )
19 18 ex ( 𝜑 → ( 𝑠𝑇 → ( 𝐹𝑠 ) ∈ ℝ ) )
20 19 anim1d ( 𝜑 → ( ( 𝑠𝑇 ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) → ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) ) )
21 20 eximdv ( 𝜑 → ( ∃ 𝑠 ( 𝑠𝑇 ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) → ∃ 𝑠 ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) ) )
22 16 21 mpd ( 𝜑 → ∃ 𝑠 ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) )
23 17 ffvelrnda ( ( 𝜑𝑡𝑇 ) → ( 𝐹𝑡 ) ∈ ℝ )
24 23 ex ( 𝜑 → ( 𝑡𝑇 → ( 𝐹𝑡 ) ∈ ℝ ) )
25 2 24 ralrimi ( 𝜑 → ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ )
26 19.41v ( ∃ 𝑠 ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ↔ ( ∃ 𝑠 ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) )
27 22 25 26 sylanbrc ( 𝜑 → ∃ 𝑠 ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) )
28 df-3an ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ↔ ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) )
29 28 exbii ( ∃ 𝑠 ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ↔ ∃ 𝑠 ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) )
30 27 29 sylibr ( 𝜑 → ∃ 𝑠 ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) )
31 nfcv 𝑡 𝑠
32 1 31 nffv 𝑡 ( 𝐹𝑠 )
33 32 nfel1 𝑡 ( 𝐹𝑠 ) ∈ ℝ
34 nfra1 𝑡𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 )
35 nfra1 𝑡𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ
36 33 34 35 nf3an 𝑡 ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ )
37 nfv 𝑡 𝑛 ∈ ℕ
38 nfcv 𝑡 <
39 nfcv 𝑡 𝑛
40 32 38 39 nfbr 𝑡 ( 𝐹𝑠 ) < 𝑛
41 37 40 nfan 𝑡 ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 )
42 36 41 nfan 𝑡 ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) )
43 simpll3 ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ )
44 simpr ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → 𝑡𝑇 )
45 rsp ( ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ → ( 𝑡𝑇 → ( 𝐹𝑡 ) ∈ ℝ ) )
46 43 44 45 sylc ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → ( 𝐹𝑡 ) ∈ ℝ )
47 simpll1 ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → ( 𝐹𝑠 ) ∈ ℝ )
48 simplrl ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → 𝑛 ∈ ℕ )
49 48 nnred ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → 𝑛 ∈ ℝ )
50 simpl2 ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) → ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) )
51 50 r19.21bi ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) )
52 simplrr ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → ( 𝐹𝑠 ) < 𝑛 )
53 46 47 49 51 52 lelttrd ( ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) ∧ 𝑡𝑇 ) → ( 𝐹𝑡 ) < 𝑛 )
54 53 ex ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) → ( 𝑡𝑇 → ( 𝐹𝑡 ) < 𝑛 ) )
55 42 54 ralrimi ( ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) ∧ ( 𝑛 ∈ ℕ ∧ ( 𝐹𝑠 ) < 𝑛 ) ) → ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 )
56 arch ( ( 𝐹𝑠 ) ∈ ℝ → ∃ 𝑛 ∈ ℕ ( 𝐹𝑠 ) < 𝑛 )
57 56 3ad2ant1 ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) → ∃ 𝑛 ∈ ℕ ( 𝐹𝑠 ) < 𝑛 )
58 55 57 reximddv ( ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) → ∃ 𝑛 ∈ ℕ ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 )
59 58 eximi ( ∃ 𝑠 ( ( 𝐹𝑠 ) ∈ ℝ ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ≤ ( 𝐹𝑠 ) ∧ ∀ 𝑡𝑇 ( 𝐹𝑡 ) ∈ ℝ ) → ∃ 𝑠𝑛 ∈ ℕ ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 )
60 30 59 syl ( 𝜑 → ∃ 𝑠𝑛 ∈ ℕ ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 )
61 19.9v ( ∃ 𝑠𝑛 ∈ ℕ ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 ↔ ∃ 𝑛 ∈ ℕ ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 )
62 60 61 sylib ( 𝜑 → ∃ 𝑛 ∈ ℕ ∀ 𝑡𝑇 ( 𝐹𝑡 ) < 𝑛 )