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Mirrors > Home > MPE Home > Th. List > fiinbas | Structured version Visualization version Unicode version |
Description: If a set is closed under finite intersection, then it is a basis for a topology. (Contributed by Jeff Madsen, 2-Sep-2009.) |
Ref | Expression |
---|---|
fiinbas |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | ssid 3624 | . . . . . . . 8 | |
2 | eleq2 2690 | . . . . . . . . . 10 | |
3 | sseq1 3626 | . . . . . . . . . 10 | |
4 | 2, 3 | anbi12d 747 | . . . . . . . . 9 |
5 | 4 | rspcev 3309 | . . . . . . . 8 |
6 | 1, 5 | mpanr2 720 | . . . . . . 7 |
7 | 6 | ralrimiva 2966 | . . . . . 6 |
8 | 7 | a1i 11 | . . . . 5 |
9 | 8 | ralimdv 2963 | . . . 4 |
10 | 9 | ralimdv 2963 | . . 3 |
11 | isbasis2g 20752 | . . 3 | |
12 | 10, 11 | sylibrd 249 | . 2 |
13 | 12 | imp 445 | 1 |
Colors of variables: wff setvar class |
Syntax hints: wi 4 wa 384 wceq 1483 wcel 1990 wral 2912 wrex 2913 cin 3573 wss 3574 ctb 20749 |
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-9 1999 ax-10 2019 ax-11 2034 ax-12 2047 ax-13 2246 ax-ext 2602 |
This theorem depends on definitions: df-bi 197 df-or 385 df-an 386 df-tru 1486 df-ex 1705 df-nf 1710 df-sb 1881 df-clab 2609 df-cleq 2615 df-clel 2618 df-nfc 2753 df-ral 2917 df-rex 2918 df-v 3202 df-in 3581 df-ss 3588 df-pw 4160 df-uni 4437 df-bases 20750 |
This theorem is referenced by: fibas 20781 qtopbaslem 22562 ontopbas 32427 isbasisrelowl 33206 |
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