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Description: The inner product operation of a subcomplex pre-Hilbert space is continuous. (Contributed by Mario Carneiro, 13-Oct-2015)
| Ref | Expression | ||
|---|---|---|---|
| Hypotheses | ipcn.v | ⊢ 𝑉 = ( Base ‘ 𝑊 ) | |
| ipcn.h | ⊢ , = ( ·𝑖 ‘ 𝑊 ) | ||
| ipcn.d | ⊢ 𝐷 = ( dist ‘ 𝑊 ) | ||
| ipcn.n | ⊢ 𝑁 = ( norm ‘ 𝑊 ) | ||
| ipcn.t | ⊢ 𝑇 = ( ( 𝑅 / 2 ) / ( ( 𝑁 ‘ 𝐴 ) + 1 ) ) | ||
| ipcn.u | ⊢ 𝑈 = ( ( 𝑅 / 2 ) / ( ( 𝑁 ‘ 𝐵 ) + 𝑇 ) ) | ||
| ipcn.w | ⊢ ( 𝜑 → 𝑊 ∈ ℂPreHil ) | ||
| ipcn.a | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | ||
| ipcn.b | ⊢ ( 𝜑 → 𝐵 ∈ 𝑉 ) | ||
| ipcn.r | ⊢ ( 𝜑 → 𝑅 ∈ ℝ+ ) | ||
| Assertion | ipcnlem1 | ⊢ ( 𝜑 → ∃ 𝑟 ∈ ℝ+ ∀ 𝑥 ∈ 𝑉 ∀ 𝑦 ∈ 𝑉 ( ( ( 𝐴 𝐷 𝑥 ) < 𝑟 ∧ ( 𝐵 𝐷 𝑦 ) < 𝑟 ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) |
| Step | Hyp | Ref | Expression |
|---|---|---|---|
| 1 | ipcn.v | ⊢ 𝑉 = ( Base ‘ 𝑊 ) | |
| 2 | ipcn.h | ⊢ , = ( ·𝑖 ‘ 𝑊 ) | |
| 3 | ipcn.d | ⊢ 𝐷 = ( dist ‘ 𝑊 ) | |
| 4 | ipcn.n | ⊢ 𝑁 = ( norm ‘ 𝑊 ) | |
| 5 | ipcn.t | ⊢ 𝑇 = ( ( 𝑅 / 2 ) / ( ( 𝑁 ‘ 𝐴 ) + 1 ) ) | |
| 6 | ipcn.u | ⊢ 𝑈 = ( ( 𝑅 / 2 ) / ( ( 𝑁 ‘ 𝐵 ) + 𝑇 ) ) | |
| 7 | ipcn.w | ⊢ ( 𝜑 → 𝑊 ∈ ℂPreHil ) | |
| 8 | ipcn.a | ⊢ ( 𝜑 → 𝐴 ∈ 𝑉 ) | |
| 9 | ipcn.b | ⊢ ( 𝜑 → 𝐵 ∈ 𝑉 ) | |
| 10 | ipcn.r | ⊢ ( 𝜑 → 𝑅 ∈ ℝ+ ) | |
| 11 | 10 | rphalfcld | ⊢ ( 𝜑 → ( 𝑅 / 2 ) ∈ ℝ+ ) |
| 12 | cphnlm | ⊢ ( 𝑊 ∈ ℂPreHil → 𝑊 ∈ NrmMod ) | |
| 13 | 7 12 | syl | ⊢ ( 𝜑 → 𝑊 ∈ NrmMod ) |
| 14 | nlmngp | ⊢ ( 𝑊 ∈ NrmMod → 𝑊 ∈ NrmGrp ) | |
| 15 | 13 14 | syl | ⊢ ( 𝜑 → 𝑊 ∈ NrmGrp ) |
| 16 | 1 4 | nmcl | ⊢ ( ( 𝑊 ∈ NrmGrp ∧ 𝐴 ∈ 𝑉 ) → ( 𝑁 ‘ 𝐴 ) ∈ ℝ ) |
| 17 | 15 8 16 | syl2anc | ⊢ ( 𝜑 → ( 𝑁 ‘ 𝐴 ) ∈ ℝ ) |
| 18 | 1 4 | nmge0 | ⊢ ( ( 𝑊 ∈ NrmGrp ∧ 𝐴 ∈ 𝑉 ) → 0 ≤ ( 𝑁 ‘ 𝐴 ) ) |
| 19 | 15 8 18 | syl2anc | ⊢ ( 𝜑 → 0 ≤ ( 𝑁 ‘ 𝐴 ) ) |
| 20 | 17 19 | ge0p1rpd | ⊢ ( 𝜑 → ( ( 𝑁 ‘ 𝐴 ) + 1 ) ∈ ℝ+ ) |
| 21 | 11 20 | rpdivcld | ⊢ ( 𝜑 → ( ( 𝑅 / 2 ) / ( ( 𝑁 ‘ 𝐴 ) + 1 ) ) ∈ ℝ+ ) |
| 22 | 5 21 | eqeltrid | ⊢ ( 𝜑 → 𝑇 ∈ ℝ+ ) |
| 23 | 1 4 | nmcl | ⊢ ( ( 𝑊 ∈ NrmGrp ∧ 𝐵 ∈ 𝑉 ) → ( 𝑁 ‘ 𝐵 ) ∈ ℝ ) |
| 24 | 15 9 23 | syl2anc | ⊢ ( 𝜑 → ( 𝑁 ‘ 𝐵 ) ∈ ℝ ) |
| 25 | 22 | rpred | ⊢ ( 𝜑 → 𝑇 ∈ ℝ ) |
| 26 | 24 25 | readdcld | ⊢ ( 𝜑 → ( ( 𝑁 ‘ 𝐵 ) + 𝑇 ) ∈ ℝ ) |
| 27 | 0red | ⊢ ( 𝜑 → 0 ∈ ℝ ) | |
| 28 | 1 4 | nmge0 | ⊢ ( ( 𝑊 ∈ NrmGrp ∧ 𝐵 ∈ 𝑉 ) → 0 ≤ ( 𝑁 ‘ 𝐵 ) ) |
| 29 | 15 9 28 | syl2anc | ⊢ ( 𝜑 → 0 ≤ ( 𝑁 ‘ 𝐵 ) ) |
| 30 | 24 22 | ltaddrpd | ⊢ ( 𝜑 → ( 𝑁 ‘ 𝐵 ) < ( ( 𝑁 ‘ 𝐵 ) + 𝑇 ) ) |
| 31 | 27 24 26 29 30 | lelttrd | ⊢ ( 𝜑 → 0 < ( ( 𝑁 ‘ 𝐵 ) + 𝑇 ) ) |
| 32 | 26 31 | elrpd | ⊢ ( 𝜑 → ( ( 𝑁 ‘ 𝐵 ) + 𝑇 ) ∈ ℝ+ ) |
| 33 | 11 32 | rpdivcld | ⊢ ( 𝜑 → ( ( 𝑅 / 2 ) / ( ( 𝑁 ‘ 𝐵 ) + 𝑇 ) ) ∈ ℝ+ ) |
| 34 | 6 33 | eqeltrid | ⊢ ( 𝜑 → 𝑈 ∈ ℝ+ ) |
| 35 | 22 34 | ifcld | ⊢ ( 𝜑 → if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∈ ℝ+ ) |
| 36 | 7 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑊 ∈ ℂPreHil ) |
| 37 | 8 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝐴 ∈ 𝑉 ) |
| 38 | 9 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝐵 ∈ 𝑉 ) |
| 39 | 10 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑅 ∈ ℝ+ ) |
| 40 | simprll | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑥 ∈ 𝑉 ) | |
| 41 | simprlr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑦 ∈ 𝑉 ) | |
| 42 | 15 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑊 ∈ NrmGrp ) |
| 43 | ngpms | ⊢ ( 𝑊 ∈ NrmGrp → 𝑊 ∈ MetSp ) | |
| 44 | 42 43 | syl | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑊 ∈ MetSp ) |
| 45 | 1 3 | mscl | ⊢ ( ( 𝑊 ∈ MetSp ∧ 𝐴 ∈ 𝑉 ∧ 𝑥 ∈ 𝑉 ) → ( 𝐴 𝐷 𝑥 ) ∈ ℝ ) |
| 46 | 44 37 40 45 | syl3anc | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → ( 𝐴 𝐷 𝑥 ) ∈ ℝ ) |
| 47 | 35 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∈ ℝ+ ) |
| 48 | 47 | rpred | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∈ ℝ ) |
| 49 | 34 | rpred | ⊢ ( 𝜑 → 𝑈 ∈ ℝ ) |
| 50 | 49 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑈 ∈ ℝ ) |
| 51 | simprrl | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) | |
| 52 | 25 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑇 ∈ ℝ ) |
| 53 | min2 | ⊢ ( ( 𝑇 ∈ ℝ ∧ 𝑈 ∈ ℝ ) → if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ≤ 𝑈 ) | |
| 54 | 52 50 53 | syl2anc | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ≤ 𝑈 ) |
| 55 | 46 48 50 51 54 | ltletrd | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → ( 𝐴 𝐷 𝑥 ) < 𝑈 ) |
| 56 | 15 43 | syl | ⊢ ( 𝜑 → 𝑊 ∈ MetSp ) |
| 57 | 56 | adantr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → 𝑊 ∈ MetSp ) |
| 58 | 1 3 | mscl | ⊢ ( ( 𝑊 ∈ MetSp ∧ 𝐵 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) → ( 𝐵 𝐷 𝑦 ) ∈ ℝ ) |
| 59 | 57 38 41 58 | syl3anc | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → ( 𝐵 𝐷 𝑦 ) ∈ ℝ ) |
| 60 | simprrr | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) | |
| 61 | min1 | ⊢ ( ( 𝑇 ∈ ℝ ∧ 𝑈 ∈ ℝ ) → if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ≤ 𝑇 ) | |
| 62 | 52 50 61 | syl2anc | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ≤ 𝑇 ) |
| 63 | 59 48 52 60 62 | ltletrd | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → ( 𝐵 𝐷 𝑦 ) < 𝑇 ) |
| 64 | 1 2 3 4 5 6 36 37 38 39 40 41 55 63 | ipcnlem2 | ⊢ ( ( 𝜑 ∧ ( ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ∧ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) |
| 65 | 64 | expr | ⊢ ( ( 𝜑 ∧ ( 𝑥 ∈ 𝑉 ∧ 𝑦 ∈ 𝑉 ) ) → ( ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) |
| 66 | 65 | ralrimivva | ⊢ ( 𝜑 → ∀ 𝑥 ∈ 𝑉 ∀ 𝑦 ∈ 𝑉 ( ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) |
| 67 | breq2 | ⊢ ( 𝑟 = if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) → ( ( 𝐴 𝐷 𝑥 ) < 𝑟 ↔ ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) | |
| 68 | breq2 | ⊢ ( 𝑟 = if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) → ( ( 𝐵 𝐷 𝑦 ) < 𝑟 ↔ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) | |
| 69 | 67 68 | anbi12d | ⊢ ( 𝑟 = if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) → ( ( ( 𝐴 𝐷 𝑥 ) < 𝑟 ∧ ( 𝐵 𝐷 𝑦 ) < 𝑟 ) ↔ ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) ) ) |
| 70 | 69 | imbi1d | ⊢ ( 𝑟 = if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) → ( ( ( ( 𝐴 𝐷 𝑥 ) < 𝑟 ∧ ( 𝐵 𝐷 𝑦 ) < 𝑟 ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ↔ ( ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) ) |
| 71 | 70 | 2ralbidv | ⊢ ( 𝑟 = if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) → ( ∀ 𝑥 ∈ 𝑉 ∀ 𝑦 ∈ 𝑉 ( ( ( 𝐴 𝐷 𝑥 ) < 𝑟 ∧ ( 𝐵 𝐷 𝑦 ) < 𝑟 ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ↔ ∀ 𝑥 ∈ 𝑉 ∀ 𝑦 ∈ 𝑉 ( ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) ) |
| 72 | 71 | rspcev | ⊢ ( ( if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∈ ℝ+ ∧ ∀ 𝑥 ∈ 𝑉 ∀ 𝑦 ∈ 𝑉 ( ( ( 𝐴 𝐷 𝑥 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ∧ ( 𝐵 𝐷 𝑦 ) < if ( 𝑇 ≤ 𝑈 , 𝑇 , 𝑈 ) ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) → ∃ 𝑟 ∈ ℝ+ ∀ 𝑥 ∈ 𝑉 ∀ 𝑦 ∈ 𝑉 ( ( ( 𝐴 𝐷 𝑥 ) < 𝑟 ∧ ( 𝐵 𝐷 𝑦 ) < 𝑟 ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) |
| 73 | 35 66 72 | syl2anc | ⊢ ( 𝜑 → ∃ 𝑟 ∈ ℝ+ ∀ 𝑥 ∈ 𝑉 ∀ 𝑦 ∈ 𝑉 ( ( ( 𝐴 𝐷 𝑥 ) < 𝑟 ∧ ( 𝐵 𝐷 𝑦 ) < 𝑟 ) → ( abs ‘ ( ( 𝐴 , 𝐵 ) − ( 𝑥 , 𝑦 ) ) ) < 𝑅 ) ) |