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Theorem eliotaeu 5315
Description: An inhabited iota expression has a unique value. (Contributed by Jim Kingdon, 22-Nov-2024.)
Assertion
Ref Expression
eliotaeu  |-  ( A  e.  ( iota x ph )  ->  E! x ph )

Proof of Theorem eliotaeu
Dummy variable  y is distinct from all other variables.
StepHypRef Expression
1 exsimpr 1666 . 2  |-  ( E. y ( A  e.  y  /\  A. x
( ph  <->  x  =  y
) )  ->  E. y A. x ( ph  <->  x  =  y ) )
2 eliota 5314 . 2  |-  ( A  e.  ( iota x ph )  <->  E. y ( A  e.  y  /\  A. x ( ph  <->  x  =  y ) ) )
3 df-eu 2082 . 2  |-  ( E! x ph  <->  E. y A. x ( ph  <->  x  =  y ) )
41, 2, 33imtr4i 201 1  |-  ( A  e.  ( iota x ph )  ->  E! x ph )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    <-> wb 105   A.wal 1395   E.wex 1540   E!weu 2079    e. wcel 2202   iotacio 5284
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 716  ax-5 1495  ax-7 1496  ax-gen 1497  ax-ie1 1541  ax-ie2 1542  ax-8 1552  ax-10 1553  ax-11 1554  ax-i12 1555  ax-bndl 1557  ax-4 1558  ax-17 1574  ax-i9 1578  ax-ial 1582  ax-i5r 1583  ax-ext 2213
This theorem depends on definitions:  df-bi 117  df-tru 1400  df-nf 1509  df-sb 1811  df-eu 2082  df-clab 2218  df-cleq 2224  df-clel 2227  df-nfc 2363  df-rex 2516  df-v 2804  df-sn 3675  df-uni 3894  df-iota 5286
This theorem is referenced by:  iotam  5318  elfvm  5672  elfvfvex  5673  fvmbr  5674
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