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Theorem reu5 2678
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 2061 . 2  |-  ( E! x ( x  e.  A  /\  ph )  <->  ( E. x ( x  e.  A  /\  ph )  /\  E* x ( x  e.  A  /\  ph ) ) )
2 df-reu 2451 . 2  |-  ( E! x  e.  A  ph  <->  E! x ( x  e.  A  /\  ph )
)
3 df-rex 2450 . . 3  |-  ( E. x  e.  A  ph  <->  E. x ( x  e.  A  /\  ph )
)
4 df-rmo 2452 . . 3  |-  ( E* x  e.  A  ph  <->  E* x ( x  e.  A  /\  ph )
)
53, 4anbi12i 456 . 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 211 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 103    <-> wb 104   E.wex 1480   E!weu 2014   E*wmo 2015    e. wcel 2136   E.wrex 2445   E!wreu 2446   E*wrmo 2447
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523
This theorem depends on definitions:  df-bi 116  df-nf 1449  df-sb 1751  df-eu 2017  df-mo 2018  df-rex 2450  df-reu 2451  df-rmo 2452
This theorem is referenced by:  reurex  2679  reurmo  2680  reu4  2920  reueq  2925  reusv1  4436  fncnv  5254  moriotass  5826  supeuti  6959  infeuti  6994  lteupri  7558  elrealeu  7770  rereceu  7830  exbtwnz  10186  rersqreu  10970  divalglemeunn  11858  divalglemeuneg  11860  bezoutlemeu  11940  pw2dvdseu  12100  ismgmid  12608  dedekindeu  13251  dedekindicclemicc  13260
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