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Theorem fvmbr 5674
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 5334 . . 3  |-  ( F `
 X )  =  ( iota w X F w )
21eqcomi 2235 . 2  |-  ( iota
w X F w )  =  ( F `
 X )
3 elfvfvex 5673 . . 3  |-  ( A  e.  ( F `  X )  ->  ( F `  X )  e.  _V )
4 eliotaeu 5315 . . . 4  |-  ( A  e.  ( iota w X F w )  ->  E! w  X F w )
54, 1eleq2s 2326 . . 3  |-  ( A  e.  ( F `  X )  ->  E! w  X F w )
6 breq2 4092 . . . 4  |-  ( w  =  ( F `  X )  ->  ( X F w  <->  X F
( F `  X
) ) )
76iota2 5316 . . 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 1397   E!weu 2079    e. wcel 2202   _Vcvv 2802   class class class wbr 4088   iotacio 5284   ` cfv 5326
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-3an 1006  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-sbc 3032  df-un 3204  df-sn 3675  df-pr 3676  df-op 3678  df-uni 3894  df-br 4089  df-iota 5286  df-fv 5334
This theorem is referenced by:  wlkvtxiedg  16195  wlkvtxiedgg  16196
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