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Mirrors > Home > MPE Home > Th. List > re2ndc | Structured version Visualization version GIF version |
Description: The standard topology on the reals is second-countable. (Contributed by Mario Carneiro, 21-Mar-2015.) |
Ref | Expression |
---|---|
re2ndc | ⊢ (topGen‘ran (,)) ∈ 2nd𝜔 |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | eqid 2622 | . . 3 ⊢ (topGen‘((,) “ (ℚ × ℚ))) = (topGen‘((,) “ (ℚ × ℚ))) | |
2 | 1 | tgqioo 22603 | . 2 ⊢ (topGen‘ran (,)) = (topGen‘((,) “ (ℚ × ℚ))) |
3 | qtopbas 22563 | . . 3 ⊢ ((,) “ (ℚ × ℚ)) ∈ TopBases | |
4 | omelon 8543 | . . . . . 6 ⊢ ω ∈ On | |
5 | qnnen 14942 | . . . . . . . . 9 ⊢ ℚ ≈ ℕ | |
6 | xpen 8123 | . . . . . . . . 9 ⊢ ((ℚ ≈ ℕ ∧ ℚ ≈ ℕ) → (ℚ × ℚ) ≈ (ℕ × ℕ)) | |
7 | 5, 5, 6 | mp2an 708 | . . . . . . . 8 ⊢ (ℚ × ℚ) ≈ (ℕ × ℕ) |
8 | xpnnen 14939 | . . . . . . . 8 ⊢ (ℕ × ℕ) ≈ ℕ | |
9 | 7, 8 | entri 8010 | . . . . . . 7 ⊢ (ℚ × ℚ) ≈ ℕ |
10 | nnenom 12779 | . . . . . . 7 ⊢ ℕ ≈ ω | |
11 | 9, 10 | entr2i 8011 | . . . . . 6 ⊢ ω ≈ (ℚ × ℚ) |
12 | isnumi 8772 | . . . . . 6 ⊢ ((ω ∈ On ∧ ω ≈ (ℚ × ℚ)) → (ℚ × ℚ) ∈ dom card) | |
13 | 4, 11, 12 | mp2an 708 | . . . . 5 ⊢ (ℚ × ℚ) ∈ dom card |
14 | ioof 12271 | . . . . . . 7 ⊢ (,):(ℝ* × ℝ*)⟶𝒫 ℝ | |
15 | ffun 6048 | . . . . . . 7 ⊢ ((,):(ℝ* × ℝ*)⟶𝒫 ℝ → Fun (,)) | |
16 | 14, 15 | ax-mp 5 | . . . . . 6 ⊢ Fun (,) |
17 | qssre 11798 | . . . . . . . . 9 ⊢ ℚ ⊆ ℝ | |
18 | ressxr 10083 | . . . . . . . . 9 ⊢ ℝ ⊆ ℝ* | |
19 | 17, 18 | sstri 3612 | . . . . . . . 8 ⊢ ℚ ⊆ ℝ* |
20 | xpss12 5225 | . . . . . . . 8 ⊢ ((ℚ ⊆ ℝ* ∧ ℚ ⊆ ℝ*) → (ℚ × ℚ) ⊆ (ℝ* × ℝ*)) | |
21 | 19, 19, 20 | mp2an 708 | . . . . . . 7 ⊢ (ℚ × ℚ) ⊆ (ℝ* × ℝ*) |
22 | 14 | fdmi 6052 | . . . . . . 7 ⊢ dom (,) = (ℝ* × ℝ*) |
23 | 21, 22 | sseqtr4i 3638 | . . . . . 6 ⊢ (ℚ × ℚ) ⊆ dom (,) |
24 | fores 6124 | . . . . . 6 ⊢ ((Fun (,) ∧ (ℚ × ℚ) ⊆ dom (,)) → ((,) ↾ (ℚ × ℚ)):(ℚ × ℚ)–onto→((,) “ (ℚ × ℚ))) | |
25 | 16, 23, 24 | mp2an 708 | . . . . 5 ⊢ ((,) ↾ (ℚ × ℚ)):(ℚ × ℚ)–onto→((,) “ (ℚ × ℚ)) |
26 | fodomnum 8880 | . . . . 5 ⊢ ((ℚ × ℚ) ∈ dom card → (((,) ↾ (ℚ × ℚ)):(ℚ × ℚ)–onto→((,) “ (ℚ × ℚ)) → ((,) “ (ℚ × ℚ)) ≼ (ℚ × ℚ))) | |
27 | 13, 25, 26 | mp2 9 | . . . 4 ⊢ ((,) “ (ℚ × ℚ)) ≼ (ℚ × ℚ) |
28 | 9, 10 | entri 8010 | . . . 4 ⊢ (ℚ × ℚ) ≈ ω |
29 | domentr 8015 | . . . 4 ⊢ ((((,) “ (ℚ × ℚ)) ≼ (ℚ × ℚ) ∧ (ℚ × ℚ) ≈ ω) → ((,) “ (ℚ × ℚ)) ≼ ω) | |
30 | 27, 28, 29 | mp2an 708 | . . 3 ⊢ ((,) “ (ℚ × ℚ)) ≼ ω |
31 | 2ndci 21251 | . . 3 ⊢ ((((,) “ (ℚ × ℚ)) ∈ TopBases ∧ ((,) “ (ℚ × ℚ)) ≼ ω) → (topGen‘((,) “ (ℚ × ℚ))) ∈ 2nd𝜔) | |
32 | 3, 30, 31 | mp2an 708 | . 2 ⊢ (topGen‘((,) “ (ℚ × ℚ))) ∈ 2nd𝜔 |
33 | 2, 32 | eqeltri 2697 | 1 ⊢ (topGen‘ran (,)) ∈ 2nd𝜔 |
Colors of variables: wff setvar class |
Syntax hints: ∈ wcel 1990 ⊆ wss 3574 𝒫 cpw 4158 class class class wbr 4653 × cxp 5112 dom cdm 5114 ran crn 5115 ↾ cres 5116 “ cima 5117 Oncon0 5723 Fun wfun 5882 ⟶wf 5884 –onto→wfo 5886 ‘cfv 5888 ωcom 7065 ≈ cen 7952 ≼ cdom 7953 cardccrd 8761 ℝcr 9935 ℝ*cxr 10073 ℕcn 11020 ℚcq 11788 (,)cioo 12175 topGenctg 16098 TopBasesctb 20749 2nd𝜔c2ndc 21241 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1722 ax-4 1737 ax-5 1839 ax-6 1888 ax-7 1935 ax-8 1992 ax-9 1999 ax-10 2019 ax-11 2034 ax-12 2047 ax-13 2246 ax-ext 2602 ax-rep 4771 ax-sep 4781 ax-nul 4789 ax-pow 4843 ax-pr 4906 ax-un 6949 ax-inf2 8538 ax-cnex 9992 ax-resscn 9993 ax-1cn 9994 ax-icn 9995 ax-addcl 9996 ax-addrcl 9997 ax-mulcl 9998 ax-mulrcl 9999 ax-mulcom 10000 ax-addass 10001 ax-mulass 10002 ax-distr 10003 ax-i2m1 10004 ax-1ne0 10005 ax-1rid 10006 ax-rnegex 10007 ax-rrecex 10008 ax-cnre 10009 ax-pre-lttri 10010 ax-pre-lttrn 10011 ax-pre-ltadd 10012 ax-pre-mulgt0 10013 ax-pre-sup 10014 |
This theorem depends on definitions: df-bi 197 df-or 385 df-an 386 df-3or 1038 df-3an 1039 df-tru 1486 df-ex 1705 df-nf 1710 df-sb 1881 df-eu 2474 df-mo 2475 df-clab 2609 df-cleq 2615 df-clel 2618 df-nfc 2753 df-ne 2795 df-nel 2898 df-ral 2917 df-rex 2918 df-reu 2919 df-rmo 2920 df-rab 2921 df-v 3202 df-sbc 3436 df-csb 3534 df-dif 3577 df-un 3579 df-in 3581 df-ss 3588 df-pss 3590 df-nul 3916 df-if 4087 df-pw 4160 df-sn 4178 df-pr 4180 df-tp 4182 df-op 4184 df-uni 4437 df-int 4476 df-iun 4522 df-br 4654 df-opab 4713 df-mpt 4730 df-tr 4753 df-id 5024 df-eprel 5029 df-po 5035 df-so 5036 df-fr 5073 df-se 5074 df-we 5075 df-xp 5120 df-rel 5121 df-cnv 5122 df-co 5123 df-dm 5124 df-rn 5125 df-res 5126 df-ima 5127 df-pred 5680 df-ord 5726 df-on 5727 df-lim 5728 df-suc 5729 df-iota 5851 df-fun 5890 df-fn 5891 df-f 5892 df-f1 5893 df-fo 5894 df-f1o 5895 df-fv 5896 df-isom 5897 df-riota 6611 df-ov 6653 df-oprab 6654 df-mpt2 6655 df-om 7066 df-1st 7168 df-2nd 7169 df-wrecs 7407 df-recs 7468 df-rdg 7506 df-1o 7560 df-oadd 7564 df-omul 7565 df-er 7742 df-map 7859 df-en 7956 df-dom 7957 df-sdom 7958 df-fin 7959 df-sup 8348 df-inf 8349 df-oi 8415 df-card 8765 df-acn 8768 df-pnf 10076 df-mnf 10077 df-xr 10078 df-ltxr 10079 df-le 10080 df-sub 10268 df-neg 10269 df-div 10685 df-nn 11021 df-n0 11293 df-z 11378 df-uz 11688 df-q 11789 df-ioo 12179 df-topgen 16104 df-bases 20750 df-2ndc 21243 |
This theorem is referenced by: (None) |
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