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Theorem tfri2d 6304
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 6333). 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 6303 . . . . 5  |-  ( ph  ->  F  Fn  On )
4 fndm 5287 . . . . 5  |-  ( F  Fn  On  ->  dom  F  =  On )
53, 4syl 14 . . . 4  |-  ( ph  ->  dom  F  =  On )
65eleq2d 2236 . . 3  |-  ( ph  ->  ( A  e.  dom  F  <-> 
A  e.  On ) )
76biimpar 295 . 2  |-  ( (
ph  /\  A  e.  On )  ->  A  e. 
dom  F )
81tfr2a 6289 . 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 103   A.wal 1341    = wceq 1343    e. wcel 2136   _Vcvv 2726   Oncon0 4341   dom cdm 4604    |` cres 4606   Fun wfun 5182    Fn wfn 5183   ` cfv 5188  recscrecs 6272
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-in1 604  ax-in2 605  ax-io 699  ax-5 1435  ax-7 1436  ax-gen 1437  ax-ie1 1481  ax-ie2 1482  ax-8 1492  ax-10 1493  ax-11 1494  ax-i12 1495  ax-bndl 1497  ax-4 1498  ax-17 1514  ax-i9 1518  ax-ial 1522  ax-i5r 1523  ax-13 2138  ax-14 2139  ax-ext 2147  ax-coll 4097  ax-sep 4100  ax-pow 4153  ax-pr 4187  ax-un 4411  ax-setind 4514
This theorem depends on definitions:  df-bi 116  df-3an 970  df-tru 1346  df-fal 1349  df-nf 1449  df-sb 1751  df-eu 2017  df-mo 2018  df-clab 2152  df-cleq 2158  df-clel 2161  df-nfc 2297  df-ne 2337  df-ral 2449  df-rex 2450  df-reu 2451  df-rab 2453  df-v 2728  df-sbc 2952  df-csb 3046  df-dif 3118  df-un 3120  df-in 3122  df-ss 3129  df-nul 3410  df-pw 3561  df-sn 3582  df-pr 3583  df-op 3585  df-uni 3790  df-iun 3868  df-br 3983  df-opab 4044  df-mpt 4045  df-tr 4081  df-id 4271  df-iord 4344  df-on 4346  df-suc 4349  df-xp 4610  df-rel 4611  df-cnv 4612  df-co 4613  df-dm 4614  df-rn 4615  df-res 4616  df-ima 4617  df-iota 5153  df-fun 5190  df-fn 5191  df-f 5192  df-f1 5193  df-fo 5194  df-f1o 5195  df-fv 5196  df-recs 6273
This theorem is referenced by:  rdgivallem  6349
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