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Theorem neii1 19585
Description: A neighborhood is included in the topology's base set. (Contributed by NM, 12-Feb-2007.)
Hypothesis
Ref Expression
neifval.1  |-  X  = 
U. J
Assertion
Ref Expression
neii1  |-  ( ( J  e.  Top  /\  N  e.  ( ( nei `  J ) `  S ) )  ->  N  C_  X )

Proof of Theorem neii1
Dummy variable  g is distinct from all other variables.
StepHypRef Expression
1 neifval.1 . . 3  |-  X  = 
U. J
21neiss2 19580 . 2  |-  ( ( J  e.  Top  /\  N  e.  ( ( nei `  J ) `  S ) )  ->  S  C_  X )
31isnei 19582 . . . 4  |-  ( ( J  e.  Top  /\  S  C_  X )  -> 
( N  e.  ( ( nei `  J
) `  S )  <->  ( N  C_  X  /\  E. g  e.  J  ( S  C_  g  /\  g  C_  N ) ) ) )
4 simpl 457 . . . 4  |-  ( ( N  C_  X  /\  E. g  e.  J  ( S  C_  g  /\  g  C_  N ) )  ->  N  C_  X
)
53, 4syl6bi 228 . . 3  |-  ( ( J  e.  Top  /\  S  C_  X )  -> 
( N  e.  ( ( nei `  J
) `  S )  ->  N  C_  X )
)
65impancom 440 . 2  |-  ( ( J  e.  Top  /\  N  e.  ( ( nei `  J ) `  S ) )  -> 
( S  C_  X  ->  N  C_  X )
)
72, 6mpd 15 1  |-  ( ( J  e.  Top  /\  N  e.  ( ( nei `  J ) `  S ) )  ->  N  C_  X )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    /\ wa 369    = wceq 1383    e. wcel 1804   E.wrex 2794    C_ wss 3461   U.cuni 4234   ` cfv 5578   Topctop 19372   neicnei 19576
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1605  ax-4 1618  ax-5 1691  ax-6 1734  ax-7 1776  ax-8 1806  ax-9 1808  ax-10 1823  ax-11 1828  ax-12 1840  ax-13 1985  ax-ext 2421  ax-rep 4548  ax-sep 4558  ax-nul 4566  ax-pow 4615  ax-pr 4676
This theorem depends on definitions:  df-bi 185  df-or 370  df-an 371  df-3an 976  df-tru 1386  df-ex 1600  df-nf 1604  df-sb 1727  df-eu 2272  df-mo 2273  df-clab 2429  df-cleq 2435  df-clel 2438  df-nfc 2593  df-ne 2640  df-ral 2798  df-rex 2799  df-reu 2800  df-rab 2802  df-v 3097  df-sbc 3314  df-csb 3421  df-dif 3464  df-un 3466  df-in 3468  df-ss 3475  df-nul 3771  df-if 3927  df-pw 3999  df-sn 4015  df-pr 4017  df-op 4021  df-uni 4235  df-iun 4317  df-br 4438  df-opab 4496  df-mpt 4497  df-id 4785  df-xp 4995  df-rel 4996  df-cnv 4997  df-co 4998  df-dm 4999  df-rn 5000  df-res 5001  df-ima 5002  df-iota 5541  df-fun 5580  df-fn 5581  df-f 5582  df-f1 5583  df-fo 5584  df-f1o 5585  df-fv 5586  df-top 19377  df-nei 19577
This theorem is referenced by:  neisspw  19586  neiss  19588  opnnei  19599  neiuni  19601  topssnei  19603  innei  19604  neissex  19606  iscnp4  19742  llycmpkgen2  20029  neitx  20086  flimopn  20454  flfnei  20470  fclsneii  20496  fcfnei  20514  cnextcn  20545  limcflf  22263  cvmlift2lem1  28725  neiin  30126  neibastop2  30155
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