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Theorem reu5 2566
Description: Restricted uniqueness in terms of "at most one." (Contributed by NM, 23-May-1999.) (Revised by NM, 16-Jun-2017.)
Assertion
Ref Expression
reu5  |-  ( E! x  e.  A  ph  <->  ( E. x  e.  A  ph 
/\  E* x  e.  A  ph ) )

Proof of Theorem reu5
StepHypRef Expression
1 eu5 1988 . 2  |-  ( E! x ( x  e.  A  /\  ph )  <->  ( E. x ( x  e.  A  /\  ph )  /\  E* x ( x  e.  A  /\  ph ) ) )
2 df-reu 2355 . 2  |-  ( E! x  e.  A  ph  <->  E! x ( x  e.  A  /\  ph )
)
3 df-rex 2354 . . 3  |-  ( E. x  e.  A  ph  <->  E. x ( x  e.  A  /\  ph )
)
4 df-rmo 2356 . . 3  |-  ( E* x  e.  A  ph  <->  E* x ( x  e.  A  /\  ph )
)
53, 4anbi12i 447 . 2  |-  ( ( E. x  e.  A  ph 
/\  E* x  e.  A  ph )  <->  ( E. x
( x  e.  A  /\  ph )  /\  E* x ( x  e.  A  /\  ph )
) )
61, 2, 53bitr4i 210 1  |-  ( E! x  e.  A  ph  <->  ( E. x  e.  A  ph 
/\  E* x  e.  A  ph ) )
Colors of variables: wff set class
Syntax hints:    /\ wa 102    <-> wb 103   E.wex 1421    e. wcel 1433   E!weu 1941   E*wmo 1942   E.wrex 2349   E!wreu 2350   E*wrmo 2351
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 662  ax-5 1376  ax-7 1377  ax-gen 1378  ax-ie1 1422  ax-ie2 1423  ax-8 1435  ax-10 1436  ax-11 1437  ax-i12 1438  ax-bndl 1439  ax-4 1440  ax-17 1459  ax-i9 1463  ax-ial 1467  ax-i5r 1468
This theorem depends on definitions:  df-bi 115  df-nf 1390  df-sb 1686  df-eu 1944  df-mo 1945  df-rex 2354  df-reu 2355  df-rmo 2356
This theorem is referenced by:  reurex  2567  reurmo  2568  reu4  2786  reueq  2789  reusv1  4208  fncnv  4985  moriotass  5516  supeuti  6407  infeuti  6442  lteupri  6807  elrealeu  6998  rereceu  7055  qbtwnz  9260  rersqreu  9914  divalglemeunn  10321  divalglemeuneg  10323  bezoutlemeu  10396  pw2dvdseu  10546
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