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Mirrors > Home > MPE Home > Th. List > bastg | Structured version Visualization version GIF version |
Description: A member of a basis is a subset of the topology it generates. (Contributed by NM, 16-Jul-2006.) (Revised by Mario Carneiro, 10-Jan-2015.) |
Ref | Expression |
---|---|
bastg | ⊢ (𝐵 ∈ 𝑉 → 𝐵 ⊆ (topGen‘𝐵)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simpr 487 | . . . . . 6 ⊢ ((𝐵 ∈ 𝑉 ∧ 𝑥 ∈ 𝐵) → 𝑥 ∈ 𝐵) | |
2 | vex 3497 | . . . . . . . 8 ⊢ 𝑥 ∈ V | |
3 | 2 | pwid 4563 | . . . . . . 7 ⊢ 𝑥 ∈ 𝒫 𝑥 |
4 | 3 | a1i 11 | . . . . . 6 ⊢ ((𝐵 ∈ 𝑉 ∧ 𝑥 ∈ 𝐵) → 𝑥 ∈ 𝒫 𝑥) |
5 | 1, 4 | elind 4171 | . . . . 5 ⊢ ((𝐵 ∈ 𝑉 ∧ 𝑥 ∈ 𝐵) → 𝑥 ∈ (𝐵 ∩ 𝒫 𝑥)) |
6 | elssuni 4868 | . . . . 5 ⊢ (𝑥 ∈ (𝐵 ∩ 𝒫 𝑥) → 𝑥 ⊆ ∪ (𝐵 ∩ 𝒫 𝑥)) | |
7 | 5, 6 | syl 17 | . . . 4 ⊢ ((𝐵 ∈ 𝑉 ∧ 𝑥 ∈ 𝐵) → 𝑥 ⊆ ∪ (𝐵 ∩ 𝒫 𝑥)) |
8 | 7 | ex 415 | . . 3 ⊢ (𝐵 ∈ 𝑉 → (𝑥 ∈ 𝐵 → 𝑥 ⊆ ∪ (𝐵 ∩ 𝒫 𝑥))) |
9 | eltg 21565 | . . 3 ⊢ (𝐵 ∈ 𝑉 → (𝑥 ∈ (topGen‘𝐵) ↔ 𝑥 ⊆ ∪ (𝐵 ∩ 𝒫 𝑥))) | |
10 | 8, 9 | sylibrd 261 | . 2 ⊢ (𝐵 ∈ 𝑉 → (𝑥 ∈ 𝐵 → 𝑥 ∈ (topGen‘𝐵))) |
11 | 10 | ssrdv 3973 | 1 ⊢ (𝐵 ∈ 𝑉 → 𝐵 ⊆ (topGen‘𝐵)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 398 ∈ wcel 2114 ∩ cin 3935 ⊆ wss 3936 𝒫 cpw 4539 ∪ cuni 4838 ‘cfv 6355 topGenctg 16711 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1796 ax-4 1810 ax-5 1911 ax-6 1970 ax-7 2015 ax-8 2116 ax-9 2124 ax-10 2145 ax-11 2161 ax-12 2177 ax-ext 2793 ax-sep 5203 ax-nul 5210 ax-pow 5266 ax-pr 5330 ax-un 7461 |
This theorem depends on definitions: df-bi 209 df-an 399 df-or 844 df-3an 1085 df-tru 1540 df-ex 1781 df-nf 1785 df-sb 2070 df-mo 2622 df-eu 2654 df-clab 2800 df-cleq 2814 df-clel 2893 df-nfc 2963 df-ral 3143 df-rex 3144 df-rab 3147 df-v 3496 df-sbc 3773 df-dif 3939 df-un 3941 df-in 3943 df-ss 3952 df-nul 4292 df-if 4468 df-pw 4541 df-sn 4568 df-pr 4570 df-op 4574 df-uni 4839 df-br 5067 df-opab 5129 df-mpt 5147 df-id 5460 df-xp 5561 df-rel 5562 df-cnv 5563 df-co 5564 df-dm 5565 df-iota 6314 df-fun 6357 df-fv 6363 df-topgen 16717 |
This theorem is referenced by: unitg 21575 tgclb 21578 tgtop 21581 tgidm 21588 tgss3 21594 bastop2 21602 elcls3 21691 ordtopn1 21802 ordtopn2 21803 leordtval2 21820 iocpnfordt 21823 icomnfordt 21824 iooordt 21825 tgcn 21860 tgcnp 21861 tgcmp 22009 2ndcsb 22057 2ndc1stc 22059 2ndcctbss 22063 2ndcomap 22066 ptopn 22191 xkoopn 22197 txopn 22210 txbasval 22214 ptpjcn 22219 flftg 22604 alexsubb 22654 blssopn 23105 iooretop 23374 bndth 23562 ovolicc2 24123 cncombf 24259 cnmbf 24260 ordtconnlem1 31167 elmbfmvol2 31525 dya2icoseg2 31536 iccllysconn 32497 rellysconn 32498 topjoin 33713 fnemeet2 33715 fnejoin1 33716 ontgval 33779 mblfinlem3 34946 mblfinlem4 34947 ismblfin 34948 cnambfre 34955 kelac2 39685 |
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