Metamath Proof Explorer


Theorem limsupre

Description: If a sequence is bounded, then the limsup is real. (Contributed by Glauco Siliprandi, 11-Dec-2019) (Revised by AV, 13-Sep-2020)

Ref Expression
Hypotheses limsupre.1 ( 𝜑𝐵 ⊆ ℝ )
limsupre.2 ( 𝜑 → sup ( 𝐵 , ℝ* , < ) = +∞ )
limsupre.f ( 𝜑𝐹 : 𝐵 ⟶ ℝ )
limsupre.bnd ( 𝜑 → ∃ 𝑏 ∈ ℝ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) )
Assertion limsupre ( 𝜑 → ( lim sup ‘ 𝐹 ) ∈ ℝ )

Proof

Step Hyp Ref Expression
1 limsupre.1 ( 𝜑𝐵 ⊆ ℝ )
2 limsupre.2 ( 𝜑 → sup ( 𝐵 , ℝ* , < ) = +∞ )
3 limsupre.f ( 𝜑𝐹 : 𝐵 ⟶ ℝ )
4 limsupre.bnd ( 𝜑 → ∃ 𝑏 ∈ ℝ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) )
5 mnfxr -∞ ∈ ℝ*
6 5 a1i ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → -∞ ∈ ℝ* )
7 renegcl ( 𝑏 ∈ ℝ → - 𝑏 ∈ ℝ )
8 7 rexrd ( 𝑏 ∈ ℝ → - 𝑏 ∈ ℝ* )
9 8 ad2antlr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → - 𝑏 ∈ ℝ* )
10 reex ℝ ∈ V
11 10 a1i ( 𝜑 → ℝ ∈ V )
12 11 1 ssexd ( 𝜑𝐵 ∈ V )
13 3 12 fexd ( 𝜑𝐹 ∈ V )
14 limsupcl ( 𝐹 ∈ V → ( lim sup ‘ 𝐹 ) ∈ ℝ* )
15 13 14 syl ( 𝜑 → ( lim sup ‘ 𝐹 ) ∈ ℝ* )
16 15 ad2antrr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( lim sup ‘ 𝐹 ) ∈ ℝ* )
17 7 mnfltd ( 𝑏 ∈ ℝ → -∞ < - 𝑏 )
18 17 ad2antlr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → -∞ < - 𝑏 )
19 1 ad2antrr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → 𝐵 ⊆ ℝ )
20 ressxr ℝ ⊆ ℝ*
21 20 a1i ( 𝜑 → ℝ ⊆ ℝ* )
22 3 21 fssd ( 𝜑𝐹 : 𝐵 ⟶ ℝ* )
23 22 ad2antrr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → 𝐹 : 𝐵 ⟶ ℝ* )
24 2 ad2antrr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → sup ( 𝐵 , ℝ* , < ) = +∞ )
25 simpr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) )
26 nfv 𝑘 ( 𝜑𝑏 ∈ ℝ )
27 nfre1 𝑘𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 )
28 26 27 nfan 𝑘 ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) )
29 nfv 𝑗 ( 𝜑𝑏 ∈ ℝ )
30 nfv 𝑗 𝑘 ∈ ℝ
31 nfra1 𝑗𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 )
32 29 30 31 nf3an 𝑗 ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) )
33 simp13 ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) )
34 simp2 ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → 𝑗𝐵 )
35 simp3 ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → 𝑘𝑗 )
36 rspa ( ( ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ∧ 𝑗𝐵 ) → ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) )
37 36 imp ( ( ( ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ∧ 𝑗𝐵 ) ∧ 𝑘𝑗 ) → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 )
38 33 34 35 37 syl21anc ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 )
39 simp11l ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → 𝜑 )
40 3 ffvelrnda ( ( 𝜑𝑗𝐵 ) → ( 𝐹𝑗 ) ∈ ℝ )
41 39 34 40 syl2anc ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → ( 𝐹𝑗 ) ∈ ℝ )
42 simp11r ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → 𝑏 ∈ ℝ )
43 41 42 absled ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → ( ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ↔ ( - 𝑏 ≤ ( 𝐹𝑗 ) ∧ ( 𝐹𝑗 ) ≤ 𝑏 ) ) )
44 38 43 mpbid ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → ( - 𝑏 ≤ ( 𝐹𝑗 ) ∧ ( 𝐹𝑗 ) ≤ 𝑏 ) )
45 44 simpld ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → - 𝑏 ≤ ( 𝐹𝑗 ) )
46 45 3exp ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( 𝑗𝐵 → ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) )
47 32 46 ralrimi ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) )
48 47 3exp ( ( 𝜑𝑏 ∈ ℝ ) → ( 𝑘 ∈ ℝ → ( ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) → ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) ) )
49 48 adantr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( 𝑘 ∈ ℝ → ( ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) → ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) ) )
50 28 49 reximdai ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) → ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) )
51 25 50 mpd ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) )
52 breq2 ( 𝑖 = 𝑗 → ( 𝑖𝑗 ) )
53 fveq2 ( 𝑖 = 𝑗 → ( 𝐹𝑖 ) = ( 𝐹𝑗 ) )
54 53 breq2d ( 𝑖 = 𝑗 → ( - 𝑏 ≤ ( 𝐹𝑖 ) ↔ - 𝑏 ≤ ( 𝐹𝑗 ) ) )
55 52 54 imbi12d ( 𝑖 = 𝑗 → ( ( 𝑖 → - 𝑏 ≤ ( 𝐹𝑖 ) ) ↔ ( 𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) )
56 55 cbvralvw ( ∀ 𝑖𝐵 ( 𝑖 → - 𝑏 ≤ ( 𝐹𝑖 ) ) ↔ ∀ 𝑗𝐵 ( 𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) )
57 breq1 ( = 𝑘 → ( 𝑗𝑘𝑗 ) )
58 57 imbi1d ( = 𝑘 → ( ( 𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ↔ ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) )
59 58 ralbidv ( = 𝑘 → ( ∀ 𝑗𝐵 ( 𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ↔ ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) )
60 56 59 syl5bb ( = 𝑘 → ( ∀ 𝑖𝐵 ( 𝑖 → - 𝑏 ≤ ( 𝐹𝑖 ) ) ↔ ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) ) )
61 60 cbvrexvw ( ∃ ∈ ℝ ∀ 𝑖𝐵 ( 𝑖 → - 𝑏 ≤ ( 𝐹𝑖 ) ) ↔ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → - 𝑏 ≤ ( 𝐹𝑗 ) ) )
62 51 61 sylibr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ∃ ∈ ℝ ∀ 𝑖𝐵 ( 𝑖 → - 𝑏 ≤ ( 𝐹𝑖 ) ) )
63 19 23 9 24 62 limsupbnd2 ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → - 𝑏 ≤ ( lim sup ‘ 𝐹 ) )
64 6 9 16 18 63 xrltletrd ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → -∞ < ( lim sup ‘ 𝐹 ) )
65 64 4 r19.29a ( 𝜑 → -∞ < ( lim sup ‘ 𝐹 ) )
66 rexr ( 𝑏 ∈ ℝ → 𝑏 ∈ ℝ* )
67 66 ad2antlr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → 𝑏 ∈ ℝ* )
68 pnfxr +∞ ∈ ℝ*
69 68 a1i ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → +∞ ∈ ℝ* )
70 44 simprd ( ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) ∧ 𝑗𝐵𝑘𝑗 ) → ( 𝐹𝑗 ) ≤ 𝑏 )
71 70 3exp ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( 𝑗𝐵 → ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) )
72 32 71 ralrimi ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ 𝑘 ∈ ℝ ∧ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) )
73 72 3exp ( ( 𝜑𝑏 ∈ ℝ ) → ( 𝑘 ∈ ℝ → ( ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) → ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) ) )
74 73 adantr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( 𝑘 ∈ ℝ → ( ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) → ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) ) )
75 28 74 reximdai ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) → ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) )
76 25 75 mpd ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) )
77 53 breq1d ( 𝑖 = 𝑗 → ( ( 𝐹𝑖 ) ≤ 𝑏 ↔ ( 𝐹𝑗 ) ≤ 𝑏 ) )
78 52 77 imbi12d ( 𝑖 = 𝑗 → ( ( 𝑖 → ( 𝐹𝑖 ) ≤ 𝑏 ) ↔ ( 𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) )
79 78 cbvralvw ( ∀ 𝑖𝐵 ( 𝑖 → ( 𝐹𝑖 ) ≤ 𝑏 ) ↔ ∀ 𝑗𝐵 ( 𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) )
80 57 imbi1d ( = 𝑘 → ( ( 𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ↔ ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) )
81 80 ralbidv ( = 𝑘 → ( ∀ 𝑗𝐵 ( 𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ↔ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) )
82 79 81 syl5bb ( = 𝑘 → ( ∀ 𝑖𝐵 ( 𝑖 → ( 𝐹𝑖 ) ≤ 𝑏 ) ↔ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) ) )
83 82 cbvrexvw ( ∃ ∈ ℝ ∀ 𝑖𝐵 ( 𝑖 → ( 𝐹𝑖 ) ≤ 𝑏 ) ↔ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( 𝐹𝑗 ) ≤ 𝑏 ) )
84 76 83 sylibr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ∃ ∈ ℝ ∀ 𝑖𝐵 ( 𝑖 → ( 𝐹𝑖 ) ≤ 𝑏 ) )
85 19 23 67 84 limsupbnd1 ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( lim sup ‘ 𝐹 ) ≤ 𝑏 )
86 ltpnf ( 𝑏 ∈ ℝ → 𝑏 < +∞ )
87 86 ad2antlr ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → 𝑏 < +∞ )
88 16 67 69 85 87 xrlelttrd ( ( ( 𝜑𝑏 ∈ ℝ ) ∧ ∃ 𝑘 ∈ ℝ ∀ 𝑗𝐵 ( 𝑘𝑗 → ( abs ‘ ( 𝐹𝑗 ) ) ≤ 𝑏 ) ) → ( lim sup ‘ 𝐹 ) < +∞ )
89 88 4 r19.29a ( 𝜑 → ( lim sup ‘ 𝐹 ) < +∞ )
90 xrrebnd ( ( lim sup ‘ 𝐹 ) ∈ ℝ* → ( ( lim sup ‘ 𝐹 ) ∈ ℝ ↔ ( -∞ < ( lim sup ‘ 𝐹 ) ∧ ( lim sup ‘ 𝐹 ) < +∞ ) ) )
91 15 90 syl ( 𝜑 → ( ( lim sup ‘ 𝐹 ) ∈ ℝ ↔ ( -∞ < ( lim sup ‘ 𝐹 ) ∧ ( lim sup ‘ 𝐹 ) < +∞ ) ) )
92 65 89 91 mpbir2and ( 𝜑 → ( lim sup ‘ 𝐹 ) ∈ ℝ )