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Theorem fniniseg 5639
Description: Membership in the preimage of a singleton, under a function. (Contributed by Mario Carneiro, 12-May-2014.) (Proof shortened by Mario Carneiro, 28-Apr-2015.)
Assertion
Ref Expression
fniniseg  |-  ( F  Fn  A  ->  ( C  e.  ( `' F " { B }
)  <->  ( C  e.  A  /\  ( F `
 C )  =  B ) ) )

Proof of Theorem fniniseg
StepHypRef Expression
1 elpreima 5638 . 2  |-  ( F  Fn  A  ->  ( C  e.  ( `' F " { B }
)  <->  ( C  e.  A  /\  ( F `
 C )  e. 
{ B } ) ) )
2 funfvex 5534 . . . . 5  |-  ( ( Fun  F  /\  C  e.  dom  F )  -> 
( F `  C
)  e.  _V )
3 elsng 3609 . . . . 5  |-  ( ( F `  C )  e.  _V  ->  (
( F `  C
)  e.  { B } 
<->  ( F `  C
)  =  B ) )
42, 3syl 14 . . . 4  |-  ( ( Fun  F  /\  C  e.  dom  F )  -> 
( ( F `  C )  e.  { B }  <->  ( F `  C )  =  B ) )
54funfni 5318 . . 3  |-  ( ( F  Fn  A  /\  C  e.  A )  ->  ( ( F `  C )  e.  { B }  <->  ( F `  C )  =  B ) )
65pm5.32da 452 . 2  |-  ( F  Fn  A  ->  (
( C  e.  A  /\  ( F `  C
)  e.  { B } )  <->  ( C  e.  A  /\  ( F `  C )  =  B ) ) )
71, 6bitrd 188 1  |-  ( F  Fn  A  ->  ( C  e.  ( `' F " { B }
)  <->  ( C  e.  A  /\  ( F `
 C )  =  B ) ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    <-> wb 105    = wceq 1353    e. wcel 2148   _Vcvv 2739   {csn 3594   `'ccnv 4627   dom cdm 4628   "cima 4631   Fun wfun 5212    Fn wfn 5213   ` cfv 5218
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-14 2151  ax-ext 2159  ax-sep 4123  ax-pow 4176  ax-pr 4211
This theorem depends on definitions:  df-bi 117  df-3an 980  df-tru 1356  df-nf 1461  df-sb 1763  df-eu 2029  df-mo 2030  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ral 2460  df-rex 2461  df-v 2741  df-sbc 2965  df-un 3135  df-in 3137  df-ss 3144  df-pw 3579  df-sn 3600  df-pr 3601  df-op 3603  df-uni 3812  df-br 4006  df-opab 4067  df-id 4295  df-xp 4634  df-rel 4635  df-cnv 4636  df-co 4637  df-dm 4638  df-rn 4639  df-res 4640  df-ima 4641  df-iota 5180  df-fun 5220  df-fn 5221  df-fv 5226
This theorem is referenced by:  pilem1  14340  taupi  14962
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