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Theorem dffun9 5423
Description: Alternate definition of a function. (Contributed by NM, 28-Mar-2007.) (Revised by NM, 16-Jun-2017.)
Assertion
Ref Expression
dffun9  |-  ( Fun 
A  <->  ( Rel  A  /\  A. x  e.  dom  A E* y  e.  ran  A  x A y ) )
Distinct variable group:    x, y, A

Proof of Theorem dffun9
StepHypRef Expression
1 dffun7 5421 . 2  |-  ( Fun 
A  <->  ( Rel  A  /\  A. x  e.  dom  A E* y  x A y ) )
2 vex 2904 . . . . . . . 8  |-  x  e. 
_V
3 vex 2904 . . . . . . . 8  |-  y  e. 
_V
42, 3brelrn 5042 . . . . . . 7  |-  ( x A y  ->  y  e.  ran  A )
54pm4.71ri 615 . . . . . 6  |-  ( x A y  <->  ( y  e.  ran  A  /\  x A y ) )
65mobii 2276 . . . . 5  |-  ( E* y  x A y  <->  E* y ( y  e. 
ran  A  /\  x A y ) )
7 df-rmo 2659 . . . . 5  |-  ( E* y  e.  ran  A  x A y  <->  E* y
( y  e.  ran  A  /\  x A y ) )
86, 7bitr4i 244 . . . 4  |-  ( E* y  x A y  <->  E* y  e.  ran  A  x A y )
98ralbii 2675 . . 3  |-  ( A. x  e.  dom  A E* y  x A y  <->  A. x  e.  dom  A E* y  e.  ran  A  x A y )
109anbi2i 676 . 2  |-  ( ( Rel  A  /\  A. x  e.  dom  A E* y  x A y )  <-> 
( Rel  A  /\  A. x  e.  dom  A E* y  e.  ran  A  x A y ) )
111, 10bitri 241 1  |-  ( Fun 
A  <->  ( Rel  A  /\  A. x  e.  dom  A E* y  e.  ran  A  x A y ) )
Colors of variables: wff set class
Syntax hints:    <-> wb 177    /\ wa 359    e. wcel 1717   E*wmo 2241   A.wral 2651   E*wrmo 2654   class class class wbr 4155   dom cdm 4820   ran crn 4821   Rel wrel 4825   Fun wfun 5390
This theorem is referenced by:  brdom4  8343
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1552  ax-5 1563  ax-17 1623  ax-9 1661  ax-8 1682  ax-14 1721  ax-6 1736  ax-7 1741  ax-11 1753  ax-12 1939  ax-ext 2370  ax-sep 4273  ax-nul 4281  ax-pr 4346
This theorem depends on definitions:  df-bi 178  df-or 360  df-an 361  df-3an 938  df-tru 1325  df-ex 1548  df-nf 1551  df-sb 1656  df-eu 2244  df-mo 2245  df-clab 2376  df-cleq 2382  df-clel 2385  df-nfc 2514  df-ne 2554  df-ral 2656  df-rmo 2659  df-rab 2660  df-v 2903  df-dif 3268  df-un 3270  df-in 3272  df-ss 3279  df-nul 3574  df-if 3685  df-sn 3765  df-pr 3766  df-op 3768  df-br 4156  df-opab 4210  df-id 4441  df-cnv 4828  df-co 4829  df-dm 4830  df-rn 4831  df-fun 5398
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