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Theorem fneu2 5686
Description: There is exactly one value of a function. (Contributed by NM, 7-Nov-1995.)
Assertion
Ref Expression
fneu2  |-  ( ( F  Fn  A  /\  B  e.  A )  ->  E! y <. B , 
y >.  e.  F )
Distinct variable groups:    y, F    y, B
Allowed substitution hint:    A( y)

Proof of Theorem fneu2
StepHypRef Expression
1 fneu 5685 . 2  |-  ( ( F  Fn  A  /\  B  e.  A )  ->  E! y  B F y )
2 df-br 4448 . . 3  |-  ( B F y  <->  <. B , 
y >.  e.  F )
32eubii 2300 . 2  |-  ( E! y  B F y  <-> 
E! y <. B , 
y >.  e.  F )
41, 3sylib 196 1  |-  ( ( F  Fn  A  /\  B  e.  A )  ->  E! y <. B , 
y >.  e.  F )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    /\ wa 369    e. wcel 1767   E!weu 2275   <.cop 4033   class class class wbr 4447    Fn wfn 5583
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1601  ax-4 1612  ax-5 1680  ax-6 1719  ax-7 1739  ax-9 1771  ax-10 1786  ax-11 1791  ax-12 1803  ax-13 1968  ax-ext 2445  ax-sep 4568  ax-nul 4576  ax-pr 4686
This theorem depends on definitions:  df-bi 185  df-or 370  df-an 371  df-3an 975  df-tru 1382  df-ex 1597  df-nf 1600  df-sb 1712  df-eu 2279  df-mo 2280  df-clab 2453  df-cleq 2459  df-clel 2462  df-nfc 2617  df-ne 2664  df-ral 2819  df-rex 2820  df-rab 2823  df-v 3115  df-dif 3479  df-un 3481  df-in 3483  df-ss 3490  df-nul 3786  df-if 3940  df-sn 4028  df-pr 4030  df-op 4034  df-br 4448  df-opab 4506  df-id 4795  df-xp 5005  df-rel 5006  df-cnv 5007  df-co 5008  df-dm 5009  df-fun 5590  df-fn 5591
This theorem is referenced by:  feu  5761
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