| Step | Hyp | Ref
| Expression |
| 1 | | methaus.1 |
. . 3
⊢ 𝐽 = (MetOpen‘𝐷) |
| 2 | 1 | mopnex 24532 |
. 2
⊢ (𝐷 ∈ (∞Met‘𝑋) → ∃𝑑 ∈ (Met‘𝑋)𝐽 = (MetOpen‘𝑑)) |
| 3 | | metxmet 24344 |
. . . . . . . . . 10
⊢ (𝑑 ∈ (Met‘𝑋) → 𝑑 ∈ (∞Met‘𝑋)) |
| 4 | 3 | ad2antrr 726 |
. . . . . . . . 9
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → 𝑑 ∈ (∞Met‘𝑋)) |
| 5 | | simplrl 777 |
. . . . . . . . 9
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → 𝑥 ∈ 𝑋) |
| 6 | | metcl 24342 |
. . . . . . . . . . . . . 14
⊢ ((𝑑 ∈ (Met‘𝑋) ∧ 𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋) → (𝑥𝑑𝑦) ∈ ℝ) |
| 7 | 6 | 3expb 1121 |
. . . . . . . . . . . . 13
⊢ ((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → (𝑥𝑑𝑦) ∈ ℝ) |
| 8 | 7 | adantr 480 |
. . . . . . . . . . . 12
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (𝑥𝑑𝑦) ∈ ℝ) |
| 9 | | metgt0 24369 |
. . . . . . . . . . . . . 14
⊢ ((𝑑 ∈ (Met‘𝑋) ∧ 𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋) → (𝑥 ≠ 𝑦 ↔ 0 < (𝑥𝑑𝑦))) |
| 10 | 9 | 3expb 1121 |
. . . . . . . . . . . . 13
⊢ ((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → (𝑥 ≠ 𝑦 ↔ 0 < (𝑥𝑑𝑦))) |
| 11 | 10 | biimpa 476 |
. . . . . . . . . . . 12
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → 0 < (𝑥𝑑𝑦)) |
| 12 | 8, 11 | elrpd 13074 |
. . . . . . . . . . 11
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (𝑥𝑑𝑦) ∈
ℝ+) |
| 13 | 12 | rphalfcld 13089 |
. . . . . . . . . 10
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → ((𝑥𝑑𝑦) / 2) ∈
ℝ+) |
| 14 | 13 | rpxrd 13078 |
. . . . . . . . 9
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → ((𝑥𝑑𝑦) / 2) ∈
ℝ*) |
| 15 | | eqid 2737 |
. . . . . . . . . 10
⊢
(MetOpen‘𝑑) =
(MetOpen‘𝑑) |
| 16 | 15 | blopn 24513 |
. . . . . . . . 9
⊢ ((𝑑 ∈ (∞Met‘𝑋) ∧ 𝑥 ∈ 𝑋 ∧ ((𝑥𝑑𝑦) / 2) ∈ ℝ*) →
(𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∈ (MetOpen‘𝑑)) |
| 17 | 4, 5, 14, 16 | syl3anc 1373 |
. . . . . . . 8
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∈ (MetOpen‘𝑑)) |
| 18 | | simplrr 778 |
. . . . . . . . 9
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → 𝑦 ∈ 𝑋) |
| 19 | 15 | blopn 24513 |
. . . . . . . . 9
⊢ ((𝑑 ∈ (∞Met‘𝑋) ∧ 𝑦 ∈ 𝑋 ∧ ((𝑥𝑑𝑦) / 2) ∈ ℝ*) →
(𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∈ (MetOpen‘𝑑)) |
| 20 | 4, 18, 14, 19 | syl3anc 1373 |
. . . . . . . 8
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∈ (MetOpen‘𝑑)) |
| 21 | | blcntr 24423 |
. . . . . . . . 9
⊢ ((𝑑 ∈ (∞Met‘𝑋) ∧ 𝑥 ∈ 𝑋 ∧ ((𝑥𝑑𝑦) / 2) ∈ ℝ+) →
𝑥 ∈ (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2))) |
| 22 | 4, 5, 13, 21 | syl3anc 1373 |
. . . . . . . 8
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → 𝑥 ∈ (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2))) |
| 23 | | blcntr 24423 |
. . . . . . . . 9
⊢ ((𝑑 ∈ (∞Met‘𝑋) ∧ 𝑦 ∈ 𝑋 ∧ ((𝑥𝑑𝑦) / 2) ∈ ℝ+) →
𝑦 ∈ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2))) |
| 24 | 4, 18, 13, 23 | syl3anc 1373 |
. . . . . . . 8
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → 𝑦 ∈ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2))) |
| 25 | 13 | rpred 13077 |
. . . . . . . . . . . 12
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → ((𝑥𝑑𝑦) / 2) ∈ ℝ) |
| 26 | 25, 25 | rexaddd 13276 |
. . . . . . . . . . 11
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (((𝑥𝑑𝑦) / 2) +𝑒 ((𝑥𝑑𝑦) / 2)) = (((𝑥𝑑𝑦) / 2) + ((𝑥𝑑𝑦) / 2))) |
| 27 | 8 | recnd 11289 |
. . . . . . . . . . . 12
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (𝑥𝑑𝑦) ∈ ℂ) |
| 28 | 27 | 2halvesd 12512 |
. . . . . . . . . . 11
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (((𝑥𝑑𝑦) / 2) + ((𝑥𝑑𝑦) / 2)) = (𝑥𝑑𝑦)) |
| 29 | 26, 28 | eqtrd 2777 |
. . . . . . . . . 10
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (((𝑥𝑑𝑦) / 2) +𝑒 ((𝑥𝑑𝑦) / 2)) = (𝑥𝑑𝑦)) |
| 30 | 8 | leidd 11829 |
. . . . . . . . . 10
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (𝑥𝑑𝑦) ≤ (𝑥𝑑𝑦)) |
| 31 | 29, 30 | eqbrtrd 5165 |
. . . . . . . . 9
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → (((𝑥𝑑𝑦) / 2) +𝑒 ((𝑥𝑑𝑦) / 2)) ≤ (𝑥𝑑𝑦)) |
| 32 | | bldisj 24408 |
. . . . . . . . 9
⊢ (((𝑑 ∈ (∞Met‘𝑋) ∧ 𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋) ∧ (((𝑥𝑑𝑦) / 2) ∈ ℝ* ∧
((𝑥𝑑𝑦) / 2) ∈ ℝ* ∧
(((𝑥𝑑𝑦) / 2) +𝑒 ((𝑥𝑑𝑦) / 2)) ≤ (𝑥𝑑𝑦))) → ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2))) = ∅) |
| 33 | 4, 5, 18, 14, 14, 31, 32 | syl33anc 1387 |
. . . . . . . 8
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2))) = ∅) |
| 34 | | eleq2 2830 |
. . . . . . . . . 10
⊢ (𝑚 = (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → (𝑥 ∈ 𝑚 ↔ 𝑥 ∈ (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)))) |
| 35 | | ineq1 4213 |
. . . . . . . . . . 11
⊢ (𝑚 = (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → (𝑚 ∩ 𝑛) = ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ 𝑛)) |
| 36 | 35 | eqeq1d 2739 |
. . . . . . . . . 10
⊢ (𝑚 = (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → ((𝑚 ∩ 𝑛) = ∅ ↔ ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ 𝑛) = ∅)) |
| 37 | 34, 36 | 3anbi13d 1440 |
. . . . . . . . 9
⊢ (𝑚 = (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → ((𝑥 ∈ 𝑚 ∧ 𝑦 ∈ 𝑛 ∧ (𝑚 ∩ 𝑛) = ∅) ↔ (𝑥 ∈ (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∧ 𝑦 ∈ 𝑛 ∧ ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ 𝑛) = ∅))) |
| 38 | | eleq2 2830 |
. . . . . . . . . 10
⊢ (𝑛 = (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → (𝑦 ∈ 𝑛 ↔ 𝑦 ∈ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)))) |
| 39 | | ineq2 4214 |
. . . . . . . . . . 11
⊢ (𝑛 = (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ 𝑛) = ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)))) |
| 40 | 39 | eqeq1d 2739 |
. . . . . . . . . 10
⊢ (𝑛 = (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → (((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ 𝑛) = ∅ ↔ ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2))) = ∅)) |
| 41 | 38, 40 | 3anbi23d 1441 |
. . . . . . . . 9
⊢ (𝑛 = (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) → ((𝑥 ∈ (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∧ 𝑦 ∈ 𝑛 ∧ ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ 𝑛) = ∅) ↔ (𝑥 ∈ (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∧ 𝑦 ∈ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∧ ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2))) = ∅))) |
| 42 | 37, 41 | rspc2ev 3635 |
. . . . . . . 8
⊢ (((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∈ (MetOpen‘𝑑) ∧ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∈ (MetOpen‘𝑑) ∧ (𝑥 ∈ (𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∧ 𝑦 ∈ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∧ ((𝑥(ball‘𝑑)((𝑥𝑑𝑦) / 2)) ∩ (𝑦(ball‘𝑑)((𝑥𝑑𝑦) / 2))) = ∅)) → ∃𝑚 ∈ (MetOpen‘𝑑)∃𝑛 ∈ (MetOpen‘𝑑)(𝑥 ∈ 𝑚 ∧ 𝑦 ∈ 𝑛 ∧ (𝑚 ∩ 𝑛) = ∅)) |
| 43 | 17, 20, 22, 24, 33, 42 | syl113anc 1384 |
. . . . . . 7
⊢ (((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) ∧ 𝑥 ≠ 𝑦) → ∃𝑚 ∈ (MetOpen‘𝑑)∃𝑛 ∈ (MetOpen‘𝑑)(𝑥 ∈ 𝑚 ∧ 𝑦 ∈ 𝑛 ∧ (𝑚 ∩ 𝑛) = ∅)) |
| 44 | 43 | ex 412 |
. . . . . 6
⊢ ((𝑑 ∈ (Met‘𝑋) ∧ (𝑥 ∈ 𝑋 ∧ 𝑦 ∈ 𝑋)) → (𝑥 ≠ 𝑦 → ∃𝑚 ∈ (MetOpen‘𝑑)∃𝑛 ∈ (MetOpen‘𝑑)(𝑥 ∈ 𝑚 ∧ 𝑦 ∈ 𝑛 ∧ (𝑚 ∩ 𝑛) = ∅))) |
| 45 | 44 | ralrimivva 3202 |
. . . . 5
⊢ (𝑑 ∈ (Met‘𝑋) → ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑋 (𝑥 ≠ 𝑦 → ∃𝑚 ∈ (MetOpen‘𝑑)∃𝑛 ∈ (MetOpen‘𝑑)(𝑥 ∈ 𝑚 ∧ 𝑦 ∈ 𝑛 ∧ (𝑚 ∩ 𝑛) = ∅))) |
| 46 | 15 | mopntopon 24449 |
. . . . . 6
⊢ (𝑑 ∈ (∞Met‘𝑋) → (MetOpen‘𝑑) ∈ (TopOn‘𝑋)) |
| 47 | | ishaus2 23359 |
. . . . . 6
⊢
((MetOpen‘𝑑)
∈ (TopOn‘𝑋)
→ ((MetOpen‘𝑑)
∈ Haus ↔ ∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑋 (𝑥 ≠ 𝑦 → ∃𝑚 ∈ (MetOpen‘𝑑)∃𝑛 ∈ (MetOpen‘𝑑)(𝑥 ∈ 𝑚 ∧ 𝑦 ∈ 𝑛 ∧ (𝑚 ∩ 𝑛) = ∅)))) |
| 48 | 3, 46, 47 | 3syl 18 |
. . . . 5
⊢ (𝑑 ∈ (Met‘𝑋) → ((MetOpen‘𝑑) ∈ Haus ↔
∀𝑥 ∈ 𝑋 ∀𝑦 ∈ 𝑋 (𝑥 ≠ 𝑦 → ∃𝑚 ∈ (MetOpen‘𝑑)∃𝑛 ∈ (MetOpen‘𝑑)(𝑥 ∈ 𝑚 ∧ 𝑦 ∈ 𝑛 ∧ (𝑚 ∩ 𝑛) = ∅)))) |
| 49 | 45, 48 | mpbird 257 |
. . . 4
⊢ (𝑑 ∈ (Met‘𝑋) → (MetOpen‘𝑑) ∈ Haus) |
| 50 | | eleq1 2829 |
. . . 4
⊢ (𝐽 = (MetOpen‘𝑑) → (𝐽 ∈ Haus ↔ (MetOpen‘𝑑) ∈ Haus)) |
| 51 | 49, 50 | syl5ibrcom 247 |
. . 3
⊢ (𝑑 ∈ (Met‘𝑋) → (𝐽 = (MetOpen‘𝑑) → 𝐽 ∈ Haus)) |
| 52 | 51 | rexlimiv 3148 |
. 2
⊢
(∃𝑑 ∈
(Met‘𝑋)𝐽 = (MetOpen‘𝑑) → 𝐽 ∈ Haus) |
| 53 | 2, 52 | syl 17 |
1
⊢ (𝐷 ∈ (∞Met‘𝑋) → 𝐽 ∈ Haus) |