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Theorem feq1 5519
Description: Equality theorem for functions. (Contributed by NM, 1-Aug-1994.)
Assertion
Ref Expression
feq1  |-  ( F  =  G  ->  ( F : A --> B  <->  G : A
--> B ) )

Proof of Theorem feq1
StepHypRef Expression
1 fneq1 5472 . . 3  |-  ( F  =  G  ->  ( F  Fn  A  <->  G  Fn  A ) )
2 rneq 5011 . . . 4  |-  ( F  =  G  ->  ran  F  =  ran  G )
32sseq1d 3277 . . 3  |-  ( F  =  G  ->  ( ran  F  C_  B  <->  ran  G  C_  B ) )
41, 3anbi12d 477 . 2  |-  ( F  =  G  ->  (
( F  Fn  A  /\  ran  F  C_  B
)  <->  ( G  Fn  A  /\  ran  G  C_  B ) ) )
5 df-f 5384 . 2  |-  ( F : A --> B  <->  ( F  Fn  A  /\  ran  F  C_  B ) )
6 df-f 5384 . 2  |-  ( G : A --> B  <->  ( G  Fn  A  /\  ran  G  C_  B ) )
74, 5, 63bitr4g 223 1  |-  ( F  =  G  ->  ( F : A --> B  <->  G : A
--> B ) )
Colors of variables:    wff set class
This proof depends on syntax axioms:    -> wi 4    /\ wa 104    <-> wb 105    = wceq 1402    C_ wss 3220   ran crn 4777    Fn wfn 5375   -->wf 5376
This proof depends on axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-ext 2220
This proof depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-v 2823  df-un 3224  df-in 3226  df-ss 3233  df-sn 3715  df-pr 3716  df-op 3718  df-br 4132  df-opab 4194  df-rel 4783  df-cnv 4784  df-co 4785  df-dm 4786  df-rn 4787  df-fun 5382  df-fn 5383  df-f 5384
This theorem is used by:  feq1d  5523  feq1i  5529  f00  5587  f0bi  5588  f0dom0  5589  fconstg  5592  f1eq1  5596  fconst2g  5933  tfrcllemsucfn  6628  tfrcllemsucaccv  6629  tfrcllembxssdm  6631  tfrcllembfn  6632  tfrcllemex  6635  tfrcllemaccex  6636  tfrcllemres  6637  tfrcl  6639  elmapg  6939  mapfset  6949  fsetsspwxp  6952  ac6sfi  7206  f1setfi  7322  updjud  7428  finomni  7486  exmidomni  7488  mkvprop  7504  1fv  10563  seqf1oglem2  10978  seqf1og  10979  iswrd  11328  isgrpinv  13918  isghm  14105  upxp  15498  txcn  15501  plyf  15963  griedg0prc  16696  dceqnconst  17317  dcapnconst  17318
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