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Theorem dfimafn2 5776
Description: Alternate definition of the image of a function as an indexed union of singletons of function values. (Contributed by Raph Levien, 20-Nov-2006.)
Assertion
Ref Expression
dfimafn2  |-  ( ( Fun  F  /\  A  C_ 
dom  F )  -> 
( F " A
)  =  U_ x  e.  A  { ( F `  x ) } )
Distinct variable groups:    x, A    x, F

Proof of Theorem dfimafn2
Dummy variable  y is distinct from all other variables.
StepHypRef Expression
1 dfimafn 5775 . . 3  |-  ( ( Fun  F  /\  A  C_ 
dom  F )  -> 
( F " A
)  =  { y  |  E. x  e.  A  ( F `  x )  =  y } )
2 iunab 4137 . . 3  |-  U_ x  e.  A  { y  |  ( F `  x )  =  y }  =  { y  |  E. x  e.  A  ( F `  x )  =  y }
31, 2syl6eqr 2486 . 2  |-  ( ( Fun  F  /\  A  C_ 
dom  F )  -> 
( F " A
)  =  U_ x  e.  A  { y  |  ( F `  x )  =  y } )
4 df-sn 3820 . . . . 5  |-  { ( F `  x ) }  =  { y  |  y  =  ( F `  x ) }
5 eqcom 2438 . . . . . 6  |-  ( y  =  ( F `  x )  <->  ( F `  x )  =  y )
65abbii 2548 . . . . 5  |-  { y  |  y  =  ( F `  x ) }  =  { y  |  ( F `  x )  =  y }
74, 6eqtri 2456 . . . 4  |-  { ( F `  x ) }  =  { y  |  ( F `  x )  =  y }
87a1i 11 . . 3  |-  ( x  e.  A  ->  { ( F `  x ) }  =  { y  |  ( F `  x )  =  y } )
98iuneq2i 4111 . 2  |-  U_ x  e.  A  { ( F `  x ) }  =  U_ x  e.  A  { y  |  ( F `  x
)  =  y }
103, 9syl6eqr 2486 1  |-  ( ( Fun  F  /\  A  C_ 
dom  F )  -> 
( F " A
)  =  U_ x  e.  A  { ( F `  x ) } )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 359    = wceq 1652    e. wcel 1725   {cab 2422   E.wrex 2706    C_ wss 3320   {csn 3814   U_ciun 4093   dom cdm 4878   "cima 4881   Fun wfun 5448   ` cfv 5454
This theorem is referenced by:  uniiccdif  19470
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1555  ax-5 1566  ax-17 1626  ax-9 1666  ax-8 1687  ax-14 1729  ax-6 1744  ax-7 1749  ax-11 1761  ax-12 1950  ax-ext 2417  ax-sep 4330  ax-nul 4338  ax-pr 4403
This theorem depends on definitions:  df-bi 178  df-or 360  df-an 361  df-3an 938  df-tru 1328  df-ex 1551  df-nf 1554  df-sb 1659  df-eu 2285  df-mo 2286  df-clab 2423  df-cleq 2429  df-clel 2432  df-nfc 2561  df-ne 2601  df-ral 2710  df-rex 2711  df-rab 2714  df-v 2958  df-sbc 3162  df-dif 3323  df-un 3325  df-in 3327  df-ss 3334  df-nul 3629  df-if 3740  df-sn 3820  df-pr 3821  df-op 3823  df-uni 4016  df-iun 4095  df-br 4213  df-opab 4267  df-id 4498  df-xp 4884  df-rel 4885  df-cnv 4886  df-co 4887  df-dm 4888  df-rn 4889  df-res 4890  df-ima 4891  df-iota 5418  df-fun 5456  df-fn 5457  df-fv 5462
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