![]() |
Metamath Proof Explorer |
< Previous
Next >
Nearby theorems |
|
Mirrors > Home > MPE Home > Th. List > fibas | Structured version Visualization version GIF version |
Description: A collection of finite intersections is a basis. The initial set is a subbasis for the topology. (Contributed by Jeff Hankins, 25-Aug-2009.) (Revised by Mario Carneiro, 24-Nov-2013.) |
Ref | Expression |
---|---|
fibas | ⊢ (fi‘𝐴) ∈ TopBases |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | fvex 6910 | . 2 ⊢ (fi‘𝐴) ∈ V | |
2 | fiin 9445 | . . 3 ⊢ ((𝑥 ∈ (fi‘𝐴) ∧ 𝑦 ∈ (fi‘𝐴)) → (𝑥 ∩ 𝑦) ∈ (fi‘𝐴)) | |
3 | 2 | rgen2 3194 | . 2 ⊢ ∀𝑥 ∈ (fi‘𝐴)∀𝑦 ∈ (fi‘𝐴)(𝑥 ∩ 𝑦) ∈ (fi‘𝐴) |
4 | fiinbas 22854 | . 2 ⊢ (((fi‘𝐴) ∈ V ∧ ∀𝑥 ∈ (fi‘𝐴)∀𝑦 ∈ (fi‘𝐴)(𝑥 ∩ 𝑦) ∈ (fi‘𝐴)) → (fi‘𝐴) ∈ TopBases) | |
5 | 1, 3, 4 | mp2an 691 | 1 ⊢ (fi‘𝐴) ∈ TopBases |
Colors of variables: wff setvar class |
Syntax hints: ∈ wcel 2099 ∀wral 3058 Vcvv 3471 ∩ cin 3946 ‘cfv 6548 ficfi 9433 TopBasesctb 22847 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1790 ax-4 1804 ax-5 1906 ax-6 1964 ax-7 2004 ax-8 2101 ax-9 2109 ax-10 2130 ax-11 2147 ax-12 2167 ax-ext 2699 ax-sep 5299 ax-nul 5306 ax-pow 5365 ax-pr 5429 ax-un 7740 |
This theorem depends on definitions: df-bi 206 df-an 396 df-or 847 df-3or 1086 df-3an 1087 df-tru 1537 df-fal 1547 df-ex 1775 df-nf 1779 df-sb 2061 df-mo 2530 df-eu 2559 df-clab 2706 df-cleq 2720 df-clel 2806 df-nfc 2881 df-ne 2938 df-ral 3059 df-rex 3068 df-reu 3374 df-rab 3430 df-v 3473 df-sbc 3777 df-dif 3950 df-un 3952 df-in 3954 df-ss 3964 df-pss 3966 df-nul 4324 df-if 4530 df-pw 4605 df-sn 4630 df-pr 4632 df-op 4636 df-uni 4909 df-int 4950 df-br 5149 df-opab 5211 df-mpt 5232 df-tr 5266 df-id 5576 df-eprel 5582 df-po 5590 df-so 5591 df-fr 5633 df-we 5635 df-xp 5684 df-rel 5685 df-cnv 5686 df-co 5687 df-dm 5688 df-rn 5689 df-res 5690 df-ima 5691 df-ord 6372 df-on 6373 df-lim 6374 df-suc 6375 df-iota 6500 df-fun 6550 df-fn 6551 df-f 6552 df-f1 6553 df-fo 6554 df-f1o 6555 df-fv 6556 df-om 7871 df-en 8964 df-fin 8967 df-fi 9434 df-bases 22848 |
This theorem is referenced by: restbas 23061 ordttopon 23096 ordtopn1 23097 ordtopn2 23098 ordtrest2 23107 leordtval2 23115 2ndcsb 23352 ptbas 23482 xkotop 23491 alexsublem 23947 alexsub 23948 alexsubb 23949 alexsubALTlem3 23952 alexsubALTlem4 23953 alexsubALT 23954 ptcmplem1 23955 ordtrest2NEW 33524 topjoin 35849 |
Copyright terms: Public domain | W3C validator |