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Theorem fvmbr 5705
Description: If a function value is inhabited, the argument is related to the function value. (Contributed by Jim Kingdon, 31-Jan-2026.)
Assertion
Ref Expression
fvmbr  |-  ( A  e.  ( F `  X )  ->  X F ( F `  X ) )

Proof of Theorem fvmbr
Dummy variable  w is distinct from all other variables.
StepHypRef Expression
1 df-fv 5360 . . 3  |-  ( F `
 X )  =  ( iota w X F w )
21eqcomi 2236 . 2  |-  ( iota
w X F w )  =  ( F `
 X )
3 elfvfvex 5704 . . 3  |-  ( A  e.  ( F `  X )  ->  ( F `  X )  e.  _V )
4 eliotaeu 5341 . . . 4  |-  ( A  e.  ( iota w X F w )  ->  E! w  X F w )
54, 1eleq2s 2327 . . 3  |-  ( A  e.  ( F `  X )  ->  E! w  X F w )
6 breq2 4113 . . . 4  |-  ( w  =  ( F `  X )  ->  ( X F w  <->  X F
( F `  X
) ) )
76iota2 5342 . . 3  |-  ( ( ( F `  X
)  e.  _V  /\  E! w  X F w )  ->  ( X F ( F `  X )  <->  ( iota w X F w )  =  ( F `  X ) ) )
83, 5, 7syl2anc 411 . 2  |-  ( A  e.  ( F `  X )  ->  ( X F ( F `  X )  <->  ( iota w X F w )  =  ( F `  X ) ) )
92, 8mpbiri 168 1  |-  ( A  e.  ( F `  X )  ->  X F ( F `  X ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 105    = wceq 1398   E!weu 2080    e. wcel 2203   _Vcvv 2813   class class class wbr 4109   iotacio 5310   ` cfv 5352
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 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-ext 2214
This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-eu 2083  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-rex 2526  df-v 2815  df-sbc 3043  df-un 3215  df-sn 3695  df-pr 3696  df-op 3698  df-uni 3915  df-br 4110  df-iota 5312  df-fv 5360
This theorem is referenced by:  wlkvtxiedg  16340  wlkvtxiedgg  16341
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