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Theorem isfbas 17862
Description: The predicate " F is a filter base." Note that some authors require filter bases to be closed under pairwise intersections, but that is not necessary under our definition. One advantage of this definition is that tails in a directed set form a filter base under our meaning. (Contributed by Jeff Hankins, 1-Sep-2009.) (Revised by Mario Carneiro, 28-Jul-2015.)
Assertion
Ref Expression
isfbas  |-  ( B  e.  A  ->  ( F  e.  ( fBas `  B )  <->  ( F  C_ 
~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) ) )
Distinct variable groups:    x, y, F    x, B, y
Allowed substitution hints:    A( x, y)

Proof of Theorem isfbas
Dummy variables  z  w are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 pwexg 4384 . . . . 5  |-  ( B  e.  A  ->  ~P B  e.  _V )
2 elpw2g 4364 . . . . 5  |-  ( ~P B  e.  _V  ->  ( F  e.  ~P ~P B 
<->  F  C_  ~P B
) )
31, 2syl 16 . . . 4  |-  ( B  e.  A  ->  ( F  e.  ~P ~P B 
<->  F  C_  ~P B
) )
43anbi1d 687 . . 3  |-  ( B  e.  A  ->  (
( F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) )  <-> 
( F  C_  ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P ( x  i^i  y ) )  =/=  (/) ) ) ) )
5 elex 2965 . . . 4  |-  ( B  e.  A  ->  B  e.  _V )
65biantrurd 496 . . 3  |-  ( B  e.  A  ->  (
( F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) )  <-> 
( B  e.  _V  /\  ( F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) ) ) )
74, 6bitr3d 248 . 2  |-  ( B  e.  A  ->  (
( F  C_  ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P ( x  i^i  y ) )  =/=  (/) ) )  <->  ( B  e.  _V  /\  ( F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) ) ) )
8 df-fbas 16700 . . . 4  |-  fBas  =  ( z  e.  _V  |->  { w  e.  ~P ~P z  |  (
w  =/=  (/)  /\  (/)  e/  w  /\  A. x  e.  w  A. y  e.  w  ( w  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) } )
9 neeq1 2610 . . . . . 6  |-  ( w  =  F  ->  (
w  =/=  (/)  <->  F  =/=  (/) ) )
10 neleq2 2701 . . . . . 6  |-  ( w  =  F  ->  ( (/) 
e/  w  <->  (/)  e/  F
) )
11 ineq1 3536 . . . . . . . . 9  |-  ( w  =  F  ->  (
w  i^i  ~P (
x  i^i  y )
)  =  ( F  i^i  ~P ( x  i^i  y ) ) )
1211neeq1d 2615 . . . . . . . 8  |-  ( w  =  F  ->  (
( w  i^i  ~P ( x  i^i  y
) )  =/=  (/)  <->  ( F  i^i  ~P ( x  i^i  y ) )  =/=  (/) ) )
1312raleqbi1dv 2913 . . . . . . 7  |-  ( w  =  F  ->  ( A. y  e.  w  ( w  i^i  ~P (
x  i^i  y )
)  =/=  (/)  <->  A. y  e.  F  ( F  i^i  ~P ( x  i^i  y ) )  =/=  (/) ) )
1413raleqbi1dv 2913 . . . . . 6  |-  ( w  =  F  ->  ( A. x  e.  w  A. y  e.  w  ( w  i^i  ~P (
x  i^i  y )
)  =/=  (/)  <->  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P ( x  i^i  y ) )  =/=  (/) ) )
159, 10, 143anbi123d 1255 . . . . 5  |-  ( w  =  F  ->  (
( w  =/=  (/)  /\  (/)  e/  w  /\  A. x  e.  w  A. y  e.  w  ( w  i^i  ~P (
x  i^i  y )
)  =/=  (/) )  <->  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) )
1615adantl 454 . . . 4  |-  ( ( z  =  B  /\  w  =  F )  ->  ( ( w  =/=  (/)  /\  (/)  e/  w  /\  A. x  e.  w  A. y  e.  w  (
w  i^i  ~P (
x  i^i  y )
)  =/=  (/) )  <->  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) )
17 pweq 3803 . . . . 5  |-  ( z  =  B  ->  ~P z  =  ~P B
)
1817pweqd 3805 . . . 4  |-  ( z  =  B  ->  ~P ~P z  =  ~P ~P B )
19 vex 2960 . . . . . . 7  |-  z  e. 
_V
2019pwex 4383 . . . . . 6  |-  ~P z  e.  _V
2120pwex 4383 . . . . 5  |-  ~P ~P z  e.  _V
2221a1i 11 . . . 4  |-  ( z  e.  _V  ->  ~P ~P z  e.  _V )
238, 16, 18, 22elmptrab 17860 . . 3  |-  ( F  e.  ( fBas `  B
)  <->  ( B  e. 
_V  /\  F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) )
24 3anass 941 . . 3  |-  ( ( B  e.  _V  /\  F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P ( x  i^i  y ) )  =/=  (/) ) )  <->  ( B  e.  _V  /\  ( F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) ) )
2523, 24bitri 242 . 2  |-  ( F  e.  ( fBas `  B
)  <->  ( B  e. 
_V  /\  ( F  e.  ~P ~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) ) )
267, 25syl6rbbr 257 1  |-  ( B  e.  A  ->  ( F  e.  ( fBas `  B )  <->  ( F  C_ 
~P B  /\  ( F  =/=  (/)  /\  (/)  e/  F  /\  A. x  e.  F  A. y  e.  F  ( F  i^i  ~P (
x  i^i  y )
)  =/=  (/) ) ) ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 178    /\ wa 360    /\ w3a 937    = wceq 1653    e. wcel 1726    =/= wne 2600    e/ wnel 2601   A.wral 2706   _Vcvv 2957    i^i cin 3320    C_ wss 3321   (/)c0 3629   ~Pcpw 3800   ` cfv 5455   fBascfbas 16690
This theorem is referenced by:  fbasne0  17863  0nelfb  17864  fbsspw  17865  isfbas2  17868  trfbas2  17876  fbasweak  17898  zfbas  17929  tsmsfbas  18158  ustfilxp  18243  minveclem3b  19330
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1556  ax-5 1567  ax-17 1627  ax-9 1667  ax-8 1688  ax-13 1728  ax-14 1730  ax-6 1745  ax-7 1750  ax-11 1762  ax-12 1951  ax-ext 2418  ax-sep 4331  ax-nul 4339  ax-pow 4378  ax-pr 4404
This theorem depends on definitions:  df-bi 179  df-or 361  df-an 362  df-3an 939  df-tru 1329  df-ex 1552  df-nf 1555  df-sb 1660  df-eu 2286  df-mo 2287  df-clab 2424  df-cleq 2430  df-clel 2433  df-nfc 2562  df-ne 2602  df-nel 2603  df-ral 2711  df-rex 2712  df-rab 2715  df-v 2959  df-sbc 3163  df-csb 3253  df-dif 3324  df-un 3326  df-in 3328  df-ss 3335  df-nul 3630  df-if 3741  df-pw 3802  df-sn 3821  df-pr 3822  df-op 3824  df-uni 4017  df-br 4214  df-opab 4268  df-mpt 4269  df-id 4499  df-xp 4885  df-rel 4886  df-cnv 4887  df-co 4888  df-dm 4889  df-rn 4890  df-res 4891  df-ima 4892  df-iota 5419  df-fun 5457  df-fv 5463  df-fbas 16700
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