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Theorem eu4 2059
Description: Uniqueness using implicit substitution. (Contributed by NM, 26-Jul-1995.)
Hypothesis
Ref Expression
eu4.1  |-  ( x  =  y  ->  ( ph 
<->  ps ) )
Assertion
Ref Expression
eu4  |-  ( E! x ph  <->  ( E. x ph  /\  A. x A. y ( ( ph  /\ 
ps )  ->  x  =  y ) ) )
Distinct variable groups:    x, y    ph, y    ps, x
Allowed substitution hints:    ph( x)    ps( y)

Proof of Theorem eu4
StepHypRef Expression
1 eu5 2044 . 2  |-  ( E! x ph  <->  ( E. x ph  /\  E* x ph ) )
2 eu4.1 . . . 4  |-  ( x  =  y  ->  ( ph 
<->  ps ) )
32mo4 2058 . . 3  |-  ( E* x ph  <->  A. x A. y ( ( ph  /\ 
ps )  ->  x  =  y ) )
43anbi2i 452 . 2  |-  ( ( E. x ph  /\  E* x ph )  <->  ( E. x ph  /\  A. x A. y ( ( ph  /\ 
ps )  ->  x  =  y ) ) )
51, 4bitri 183 1  |-  ( E! x ph  <->  ( E. x ph  /\  A. x A. y ( ( ph  /\ 
ps )  ->  x  =  y ) ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103    <-> wb 104   A.wal 1329   E.wex 1468   E!weu 1997   E*wmo 1998
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 698  ax-5 1423  ax-7 1424  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-8 1482  ax-10 1483  ax-11 1484  ax-i12 1485  ax-bndl 1486  ax-4 1487  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515
This theorem depends on definitions:  df-bi 116  df-nf 1437  df-sb 1736  df-eu 2000  df-mo 2001
This theorem is referenced by:  euequ1  2092  eueq  2850  euind  2866  eusv1  4368  eroveu  6513  climeu  11058
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