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Theorem neif 12092
Description: The neighborhood function is a function from the set of the subsets of the base set of a topology. (Contributed by NM, 12-Feb-2007.) (Revised by Mario Carneiro, 11-Nov-2013.)
Hypothesis
Ref Expression
neifval.1  |-  X  = 
U. J
Assertion
Ref Expression
neif  |-  ( J  e.  Top  ->  ( nei `  J )  Fn 
~P X )

Proof of Theorem neif
Dummy variables  g  v  x are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 neifval.1 . . . . . 6  |-  X  = 
U. J
21topopn 11957 . . . . 5  |-  ( J  e.  Top  ->  X  e.  J )
3 pwexg 4044 . . . . 5  |-  ( X  e.  J  ->  ~P X  e.  _V )
4 rabexg 4011 . . . . 5  |-  ( ~P X  e.  _V  ->  { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) }  e.  _V )
52, 3, 43syl 17 . . . 4  |-  ( J  e.  Top  ->  { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) }  e.  _V )
65ralrimivw 2465 . . 3  |-  ( J  e.  Top  ->  A. x  e.  ~P  X { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) }  e.  _V )
7 eqid 2100 . . . 4  |-  ( x  e.  ~P X  |->  { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) } )  =  ( x  e.  ~P X  |->  { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) } )
87fnmpt 5185 . . 3  |-  ( A. x  e.  ~P  X { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) }  e.  _V  ->  ( x  e. 
~P X  |->  { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) } )  Fn  ~P X
)
96, 8syl 14 . 2  |-  ( J  e.  Top  ->  (
x  e.  ~P X  |->  { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) } )  Fn  ~P X )
101neifval 12091 . . 3  |-  ( J  e.  Top  ->  ( nei `  J )  =  ( x  e.  ~P X  |->  { v  e. 
~P X  |  E. g  e.  J  (
x  C_  g  /\  g  C_  v ) } ) )
1110fneq1d 5149 . 2  |-  ( J  e.  Top  ->  (
( nei `  J
)  Fn  ~P X  <->  ( x  e.  ~P X  |->  { v  e.  ~P X  |  E. g  e.  J  ( x  C_  g  /\  g  C_  v ) } )  Fn  ~P X ) )
129, 11mpbird 166 1  |-  ( J  e.  Top  ->  ( nei `  J )  Fn 
~P X )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103    = wceq 1299    e. wcel 1448   A.wral 2375   E.wrex 2376   {crab 2379   _Vcvv 2641    C_ wss 3021   ~Pcpw 3457   U.cuni 3683    |-> cmpt 3929    Fn wfn 5054   ` cfv 5059   Topctop 11946   neicnei 12089
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 671  ax-5 1391  ax-7 1392  ax-gen 1393  ax-ie1 1437  ax-ie2 1438  ax-8 1450  ax-10 1451  ax-11 1452  ax-i12 1453  ax-bndl 1454  ax-4 1455  ax-14 1460  ax-17 1474  ax-i9 1478  ax-ial 1482  ax-i5r 1483  ax-ext 2082  ax-coll 3983  ax-sep 3986  ax-pow 4038  ax-pr 4069
This theorem depends on definitions:  df-bi 116  df-3an 932  df-tru 1302  df-nf 1405  df-sb 1704  df-eu 1963  df-mo 1964  df-clab 2087  df-cleq 2093  df-clel 2096  df-nfc 2229  df-ral 2380  df-rex 2381  df-reu 2382  df-rab 2384  df-v 2643  df-sbc 2863  df-csb 2956  df-un 3025  df-in 3027  df-ss 3034  df-pw 3459  df-sn 3480  df-pr 3481  df-op 3483  df-uni 3684  df-iun 3762  df-br 3876  df-opab 3930  df-mpt 3931  df-id 4153  df-xp 4483  df-rel 4484  df-cnv 4485  df-co 4486  df-dm 4487  df-rn 4488  df-res 4489  df-ima 4490  df-iota 5024  df-fun 5061  df-fn 5062  df-f 5063  df-f1 5064  df-fo 5065  df-f1o 5066  df-fv 5067  df-top 11947  df-nei 12090
This theorem is referenced by:  neiss2  12093
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