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Mirrors > Home > MPE Home > Th. List > 2ndcredom | Structured version Visualization version GIF version |
Description: A second-countable space has at most the cardinality of the continuum. (Contributed by Mario Carneiro, 9-Apr-2015.) |
Ref | Expression |
---|---|
2ndcredom | β’ (π½ β 2ndΟ β π½ βΌ β) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | is2ndc 23305 | . 2 β’ (π½ β 2ndΟ β βπ₯ β TopBases (π₯ βΌ Ο β§ (topGenβπ₯) = π½)) | |
2 | tgdom 22836 | . . . . . 6 β’ (π₯ β TopBases β (topGenβπ₯) βΌ π« π₯) | |
3 | simpr 484 | . . . . . . . . 9 β’ ((π₯ β TopBases β§ π₯ βΌ Ο) β π₯ βΌ Ο) | |
4 | nnenom 13951 | . . . . . . . . . 10 β’ β β Ο | |
5 | 4 | ensymi 9002 | . . . . . . . . 9 β’ Ο β β |
6 | domentr 9011 | . . . . . . . . 9 β’ ((π₯ βΌ Ο β§ Ο β β) β π₯ βΌ β) | |
7 | 3, 5, 6 | sylancl 585 | . . . . . . . 8 β’ ((π₯ β TopBases β§ π₯ βΌ Ο) β π₯ βΌ β) |
8 | pwdom 9131 | . . . . . . . 8 β’ (π₯ βΌ β β π« π₯ βΌ π« β) | |
9 | 7, 8 | syl 17 | . . . . . . 7 β’ ((π₯ β TopBases β§ π₯ βΌ Ο) β π« π₯ βΌ π« β) |
10 | rpnnen 16177 | . . . . . . . 8 β’ β β π« β | |
11 | 10 | ensymi 9002 | . . . . . . 7 β’ π« β β β |
12 | domentr 9011 | . . . . . . 7 β’ ((π« π₯ βΌ π« β β§ π« β β β) β π« π₯ βΌ β) | |
13 | 9, 11, 12 | sylancl 585 | . . . . . 6 β’ ((π₯ β TopBases β§ π₯ βΌ Ο) β π« π₯ βΌ β) |
14 | domtr 9005 | . . . . . 6 β’ (((topGenβπ₯) βΌ π« π₯ β§ π« π₯ βΌ β) β (topGenβπ₯) βΌ β) | |
15 | 2, 13, 14 | syl2an2r 682 | . . . . 5 β’ ((π₯ β TopBases β§ π₯ βΌ Ο) β (topGenβπ₯) βΌ β) |
16 | breq1 5144 | . . . . 5 β’ ((topGenβπ₯) = π½ β ((topGenβπ₯) βΌ β β π½ βΌ β)) | |
17 | 15, 16 | syl5ibcom 244 | . . . 4 β’ ((π₯ β TopBases β§ π₯ βΌ Ο) β ((topGenβπ₯) = π½ β π½ βΌ β)) |
18 | 17 | expimpd 453 | . . 3 β’ (π₯ β TopBases β ((π₯ βΌ Ο β§ (topGenβπ₯) = π½) β π½ βΌ β)) |
19 | 18 | rexlimiv 3142 | . 2 β’ (βπ₯ β TopBases (π₯ βΌ Ο β§ (topGenβπ₯) = π½) β π½ βΌ β) |
20 | 1, 19 | sylbi 216 | 1 β’ (π½ β 2ndΟ β π½ βΌ β) |
Colors of variables: wff setvar class |
Syntax hints: β wi 4 β§ wa 395 = wceq 1533 β wcel 2098 βwrex 3064 π« cpw 4597 class class class wbr 5141 βcfv 6537 Οcom 7852 β cen 8938 βΌ cdom 8939 βcr 11111 βcn 12216 topGenctg 17392 TopBasesctb 22803 2ndΟc2ndc 23297 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1789 ax-4 1803 ax-5 1905 ax-6 1963 ax-7 2003 ax-8 2100 ax-9 2108 ax-10 2129 ax-11 2146 ax-12 2163 ax-ext 2697 ax-rep 5278 ax-sep 5292 ax-nul 5299 ax-pow 5356 ax-pr 5420 ax-un 7722 ax-inf2 9638 ax-cnex 11168 ax-resscn 11169 ax-1cn 11170 ax-icn 11171 ax-addcl 11172 ax-addrcl 11173 ax-mulcl 11174 ax-mulrcl 11175 ax-mulcom 11176 ax-addass 11177 ax-mulass 11178 ax-distr 11179 ax-i2m1 11180 ax-1ne0 11181 ax-1rid 11182 ax-rnegex 11183 ax-rrecex 11184 ax-cnre 11185 ax-pre-lttri 11186 ax-pre-lttrn 11187 ax-pre-ltadd 11188 ax-pre-mulgt0 11189 ax-pre-sup 11190 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 845 df-3or 1085 df-3an 1086 df-tru 1536 df-fal 1546 df-ex 1774 df-nf 1778 df-sb 2060 df-mo 2528 df-eu 2557 df-clab 2704 df-cleq 2718 df-clel 2804 df-nfc 2879 df-ne 2935 df-nel 3041 df-ral 3056 df-rex 3065 df-rmo 3370 df-reu 3371 df-rab 3427 df-v 3470 df-sbc 3773 df-csb 3889 df-dif 3946 df-un 3948 df-in 3950 df-ss 3960 df-pss 3962 df-nul 4318 df-if 4524 df-pw 4599 df-sn 4624 df-pr 4626 df-op 4630 df-uni 4903 df-int 4944 df-iun 4992 df-br 5142 df-opab 5204 df-mpt 5225 df-tr 5259 df-id 5567 df-eprel 5573 df-po 5581 df-so 5582 df-fr 5624 df-se 5625 df-we 5626 df-xp 5675 df-rel 5676 df-cnv 5677 df-co 5678 df-dm 5679 df-rn 5680 df-res 5681 df-ima 5682 df-pred 6294 df-ord 6361 df-on 6362 df-lim 6363 df-suc 6364 df-iota 6489 df-fun 6539 df-fn 6540 df-f 6541 df-f1 6542 df-fo 6543 df-f1o 6544 df-fv 6545 df-isom 6546 df-riota 7361 df-ov 7408 df-oprab 7409 df-mpo 7410 df-om 7853 df-1st 7974 df-2nd 7975 df-frecs 8267 df-wrecs 8298 df-recs 8372 df-rdg 8411 df-1o 8467 df-2o 8468 df-oadd 8471 df-omul 8472 df-er 8705 df-map 8824 df-pm 8825 df-en 8942 df-dom 8943 df-sdom 8944 df-fin 8945 df-sup 9439 df-inf 9440 df-oi 9507 df-card 9936 df-acn 9939 df-pnf 11254 df-mnf 11255 df-xr 11256 df-ltxr 11257 df-le 11258 df-sub 11450 df-neg 11451 df-div 11876 df-nn 12217 df-2 12279 df-3 12280 df-n0 12477 df-z 12563 df-uz 12827 df-q 12937 df-rp 12981 df-ico 13336 df-icc 13337 df-fz 13491 df-fzo 13634 df-fl 13763 df-seq 13973 df-exp 14033 df-hash 14296 df-cj 15052 df-re 15053 df-im 15054 df-sqrt 15188 df-abs 15189 df-limsup 15421 df-clim 15438 df-rlim 15439 df-sum 15639 df-topgen 17398 df-2ndc 23299 |
This theorem is referenced by: (None) |
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