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Theorem tfri2d 6339
Description: Principle of Transfinite Recursion, part 2 of 3. Theorem 7.41(2) of [TakeutiZaring] p. 47, with an additional condition on the recursion rule  G ( as described at tfri1 6368). Here we show that the function  F has the property that for any function  G satisfying that condition, the "next" value of  F is  G recursively applied to all "previous" values of  F. (Contributed by Jim Kingdon, 4-May-2019.)
Hypotheses
Ref Expression
tfri1d.1  |-  F  = recs ( G )
tfri1d.2  |-  ( ph  ->  A. x ( Fun 
G  /\  ( G `  x )  e.  _V ) )
Assertion
Ref Expression
tfri2d  |-  ( (
ph  /\  A  e.  On )  ->  ( F `
 A )  =  ( G `  ( F  |`  A ) ) )
Distinct variable group:    x, G
Allowed substitution hints:    ph( x)    A( x)    F( x)

Proof of Theorem tfri2d
StepHypRef Expression
1 tfri1d.1 . . . . . 6  |-  F  = recs ( G )
2 tfri1d.2 . . . . . 6  |-  ( ph  ->  A. x ( Fun 
G  /\  ( G `  x )  e.  _V ) )
31, 2tfri1d 6338 . . . . 5  |-  ( ph  ->  F  Fn  On )
4 fndm 5317 . . . . 5  |-  ( F  Fn  On  ->  dom  F  =  On )
53, 4syl 14 . . . 4  |-  ( ph  ->  dom  F  =  On )
65eleq2d 2247 . . 3  |-  ( ph  ->  ( A  e.  dom  F  <-> 
A  e.  On ) )
76biimpar 297 . 2  |-  ( (
ph  /\  A  e.  On )  ->  A  e. 
dom  F )
81tfr2a 6324 . 2  |-  ( A  e.  dom  F  -> 
( F `  A
)  =  ( G `
 ( F  |`  A ) ) )
97, 8syl 14 1  |-  ( (
ph  /\  A  e.  On )  ->  ( F `
 A )  =  ( G `  ( F  |`  A ) ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104   A.wal 1351    = wceq 1353    e. wcel 2148   _Vcvv 2739   Oncon0 4365   dom cdm 4628    |` cres 4630   Fun wfun 5212    Fn wfn 5213   ` cfv 5218  recscrecs 6307
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-in1 614  ax-in2 615  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-13 2150  ax-14 2151  ax-ext 2159  ax-coll 4120  ax-sep 4123  ax-pow 4176  ax-pr 4211  ax-un 4435  ax-setind 4538
This theorem depends on definitions:  df-bi 117  df-3an 980  df-tru 1356  df-fal 1359  df-nf 1461  df-sb 1763  df-eu 2029  df-mo 2030  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ne 2348  df-ral 2460  df-rex 2461  df-reu 2462  df-rab 2464  df-v 2741  df-sbc 2965  df-csb 3060  df-dif 3133  df-un 3135  df-in 3137  df-ss 3144  df-nul 3425  df-pw 3579  df-sn 3600  df-pr 3601  df-op 3603  df-uni 3812  df-iun 3890  df-br 4006  df-opab 4067  df-mpt 4068  df-tr 4104  df-id 4295  df-iord 4368  df-on 4370  df-suc 4373  df-xp 4634  df-rel 4635  df-cnv 4636  df-co 4637  df-dm 4638  df-rn 4639  df-res 4640  df-ima 4641  df-iota 5180  df-fun 5220  df-fn 5221  df-f 5222  df-f1 5223  df-fo 5224  df-f1o 5225  df-fv 5226  df-recs 6308
This theorem is referenced by:  rdgivallem  6384
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