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Theorem reu4 2933
Description: Restricted uniqueness using implicit substitution. (Contributed by NM, 23-Nov-1994.)
Hypothesis
Ref Expression
rmo4.1  |-  ( x  =  y  ->  ( ph 
<->  ps ) )
Assertion
Ref Expression
reu4  |-  ( E! x  e.  A  ph  <->  ( E. x  e.  A  ph 
/\  A. x  e.  A  A. y  e.  A  ( ( ph  /\  ps )  ->  x  =  y ) ) )
Distinct variable groups:    x, y, A    ph, y    ps, x
Allowed substitution hints:    ph( x)    ps( y)

Proof of Theorem reu4
StepHypRef Expression
1 reu5 2690 . 2  |-  ( E! x  e.  A  ph  <->  ( E. x  e.  A  ph 
/\  E* x  e.  A  ph ) )
2 rmo4.1 . . . 4  |-  ( x  =  y  ->  ( ph 
<->  ps ) )
32rmo4 2932 . . 3  |-  ( E* x  e.  A  ph  <->  A. x  e.  A  A. y  e.  A  (
( ph  /\  ps )  ->  x  =  y ) )
43anbi2i 457 . 2  |-  ( ( E. x  e.  A  ph 
/\  E* x  e.  A  ph )  <->  ( E. x  e.  A  ph  /\  A. x  e.  A  A. y  e.  A  (
( ph  /\  ps )  ->  x  =  y ) ) )
51, 4bitri 184 1  |-  ( E! x  e.  A  ph  <->  ( E. x  e.  A  ph 
/\  A. x  e.  A  A. y  e.  A  ( ( ph  /\  ps )  ->  x  =  y ) ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    <-> wb 105   A.wral 2455   E.wrex 2456   E!wreu 2457   E*wrmo 2458
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-io 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-ext 2159
This theorem depends on definitions:  df-bi 117  df-nf 1461  df-sb 1763  df-eu 2029  df-mo 2030  df-cleq 2170  df-clel 2173  df-ral 2460  df-rex 2461  df-reu 2462  df-rmo 2463
This theorem is referenced by:  reuind  2944  receuap  8628  lbreu  8904  cju  8920  ndvdssub  11937  qredeu  12099
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