Metamath Proof Explorer


Theorem rlimdmafv2

Description: Two ways to express that a function has a limit, analogous to rlimdm . (Contributed by AV, 5-Sep-2022)

Ref Expression
Hypotheses rlimdmafv2.1 ( 𝜑𝐹 : 𝐴 ⟶ ℂ )
rlimdmafv2.2 ( 𝜑 → sup ( 𝐴 , ℝ* , < ) = +∞ )
Assertion rlimdmafv2 ( 𝜑 → ( 𝐹 ∈ dom ⇝𝑟𝐹𝑟 ( ⇝𝑟 '''' 𝐹 ) ) )

Proof

Step Hyp Ref Expression
1 rlimdmafv2.1 ( 𝜑𝐹 : 𝐴 ⟶ ℂ )
2 rlimdmafv2.2 ( 𝜑 → sup ( 𝐴 , ℝ* , < ) = +∞ )
3 eldmg ( 𝐹 ∈ dom ⇝𝑟 → ( 𝐹 ∈ dom ⇝𝑟 ↔ ∃ 𝑥 𝐹𝑟 𝑥 ) )
4 3 ibi ( 𝐹 ∈ dom ⇝𝑟 → ∃ 𝑥 𝐹𝑟 𝑥 )
5 simpr ( ( 𝜑𝐹𝑟 𝑥 ) → 𝐹𝑟 𝑥 )
6 rlimrel Rel ⇝𝑟
7 6 brrelex1i ( 𝐹𝑟 𝑥𝐹 ∈ V )
8 7 adantl ( ( 𝜑𝐹𝑟 𝑥 ) → 𝐹 ∈ V )
9 vex 𝑥 ∈ V
10 9 a1i ( ( 𝜑𝐹𝑟 𝑥 ) → 𝑥 ∈ V )
11 breldmg ( ( 𝐹 ∈ V ∧ 𝑥 ∈ V ∧ 𝐹𝑟 𝑥 ) → 𝐹 ∈ dom ⇝𝑟 )
12 8 10 5 11 syl3anc ( ( 𝜑𝐹𝑟 𝑥 ) → 𝐹 ∈ dom ⇝𝑟 )
13 breq2 ( 𝑦 = 𝑥 → ( 𝐹𝑟 𝑦𝐹𝑟 𝑥 ) )
14 13 biimprd ( 𝑦 = 𝑥 → ( 𝐹𝑟 𝑥𝐹𝑟 𝑦 ) )
15 14 spimevw ( 𝐹𝑟 𝑥 → ∃ 𝑦 𝐹𝑟 𝑦 )
16 15 adantl ( ( 𝜑𝐹𝑟 𝑥 ) → ∃ 𝑦 𝐹𝑟 𝑦 )
17 1 adantr ( ( 𝜑𝐹𝑟 𝑥 ) → 𝐹 : 𝐴 ⟶ ℂ )
18 17 adantr ( ( ( 𝜑𝐹𝑟 𝑥 ) ∧ ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) ) → 𝐹 : 𝐴 ⟶ ℂ )
19 2 adantr ( ( 𝜑𝐹𝑟 𝑥 ) → sup ( 𝐴 , ℝ* , < ) = +∞ )
20 19 adantr ( ( ( 𝜑𝐹𝑟 𝑥 ) ∧ ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) ) → sup ( 𝐴 , ℝ* , < ) = +∞ )
21 simprl ( ( ( 𝜑𝐹𝑟 𝑥 ) ∧ ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) ) → 𝐹𝑟 𝑦 )
22 simprr ( ( ( 𝜑𝐹𝑟 𝑥 ) ∧ ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) ) → 𝐹𝑟 𝑧 )
23 18 20 21 22 rlimuni ( ( ( 𝜑𝐹𝑟 𝑥 ) ∧ ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) ) → 𝑦 = 𝑧 )
24 23 ex ( ( 𝜑𝐹𝑟 𝑥 ) → ( ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) → 𝑦 = 𝑧 ) )
25 24 alrimivv ( ( 𝜑𝐹𝑟 𝑥 ) → ∀ 𝑦𝑧 ( ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) → 𝑦 = 𝑧 ) )
26 breq2 ( 𝑦 = 𝑧 → ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) )
27 26 eu4 ( ∃! 𝑦 𝐹𝑟 𝑦 ↔ ( ∃ 𝑦 𝐹𝑟 𝑦 ∧ ∀ 𝑦𝑧 ( ( 𝐹𝑟 𝑦𝐹𝑟 𝑧 ) → 𝑦 = 𝑧 ) ) )
28 16 25 27 sylanbrc ( ( 𝜑𝐹𝑟 𝑥 ) → ∃! 𝑦 𝐹𝑟 𝑦 )
29 dfdfat2 ( ⇝𝑟 defAt 𝐹 ↔ ( 𝐹 ∈ dom ⇝𝑟 ∧ ∃! 𝑦 𝐹𝑟 𝑦 ) )
30 12 28 29 sylanbrc ( ( 𝜑𝐹𝑟 𝑥 ) → ⇝𝑟 defAt 𝐹 )
31 dfatafv2iota ( ⇝𝑟 defAt 𝐹 → ( ⇝𝑟 '''' 𝐹 ) = ( ℩ 𝑤 𝐹𝑟 𝑤 ) )
32 30 31 syl ( ( 𝜑𝐹𝑟 𝑥 ) → ( ⇝𝑟 '''' 𝐹 ) = ( ℩ 𝑤 𝐹𝑟 𝑤 ) )
33 1 adantr ( ( 𝜑 ∧ ( 𝐹𝑟 𝑥𝐹𝑟 𝑤 ) ) → 𝐹 : 𝐴 ⟶ ℂ )
34 2 adantr ( ( 𝜑 ∧ ( 𝐹𝑟 𝑥𝐹𝑟 𝑤 ) ) → sup ( 𝐴 , ℝ* , < ) = +∞ )
35 simprr ( ( 𝜑 ∧ ( 𝐹𝑟 𝑥𝐹𝑟 𝑤 ) ) → 𝐹𝑟 𝑤 )
36 simprl ( ( 𝜑 ∧ ( 𝐹𝑟 𝑥𝐹𝑟 𝑤 ) ) → 𝐹𝑟 𝑥 )
37 33 34 35 36 rlimuni ( ( 𝜑 ∧ ( 𝐹𝑟 𝑥𝐹𝑟 𝑤 ) ) → 𝑤 = 𝑥 )
38 37 expr ( ( 𝜑𝐹𝑟 𝑥 ) → ( 𝐹𝑟 𝑤𝑤 = 𝑥 ) )
39 breq2 ( 𝑤 = 𝑥 → ( 𝐹𝑟 𝑤𝐹𝑟 𝑥 ) )
40 5 39 syl5ibrcom ( ( 𝜑𝐹𝑟 𝑥 ) → ( 𝑤 = 𝑥𝐹𝑟 𝑤 ) )
41 38 40 impbid ( ( 𝜑𝐹𝑟 𝑥 ) → ( 𝐹𝑟 𝑤𝑤 = 𝑥 ) )
42 41 adantr ( ( ( 𝜑𝐹𝑟 𝑥 ) ∧ 𝑥 ∈ V ) → ( 𝐹𝑟 𝑤𝑤 = 𝑥 ) )
43 42 iota5 ( ( ( 𝜑𝐹𝑟 𝑥 ) ∧ 𝑥 ∈ V ) → ( ℩ 𝑤 𝐹𝑟 𝑤 ) = 𝑥 )
44 43 elvd ( ( 𝜑𝐹𝑟 𝑥 ) → ( ℩ 𝑤 𝐹𝑟 𝑤 ) = 𝑥 )
45 32 44 eqtrd ( ( 𝜑𝐹𝑟 𝑥 ) → ( ⇝𝑟 '''' 𝐹 ) = 𝑥 )
46 5 45 breqtrrd ( ( 𝜑𝐹𝑟 𝑥 ) → 𝐹𝑟 ( ⇝𝑟 '''' 𝐹 ) )
47 46 ex ( 𝜑 → ( 𝐹𝑟 𝑥𝐹𝑟 ( ⇝𝑟 '''' 𝐹 ) ) )
48 47 exlimdv ( 𝜑 → ( ∃ 𝑥 𝐹𝑟 𝑥𝐹𝑟 ( ⇝𝑟 '''' 𝐹 ) ) )
49 4 48 syl5 ( 𝜑 → ( 𝐹 ∈ dom ⇝𝑟𝐹𝑟 ( ⇝𝑟 '''' 𝐹 ) ) )
50 6 releldmi ( 𝐹𝑟 ( ⇝𝑟 '''' 𝐹 ) → 𝐹 ∈ dom ⇝𝑟 )
51 49 50 impbid1 ( 𝜑 → ( 𝐹 ∈ dom ⇝𝑟𝐹𝑟 ( ⇝𝑟 '''' 𝐹 ) ) )