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Theorem tfr2 6297
Description: Principle of Transfinite Recursion, part 2 of 3. Theorem 7.41(2) of [TakeutiZaring] p. 47. Here we show that the function  F has the property that for any function  G whatsoever, the "next" value of  F is  G recursively applied to all "previous" values of  F. (Contributed by NM, 9-Apr-1995.) (Revised by Stefan O'Rear, 18-Jan-2015.)
Hypothesis
Ref Expression
tfr.1  |-  F  = recs ( G )
Assertion
Ref Expression
tfr2  |-  ( A  e.  On  ->  ( F `  A )  =  ( G `  ( F  |`  A ) ) )

Proof of Theorem tfr2
StepHypRef Expression
1 tfr.1 . . . . 5  |-  F  = recs ( G )
21tfr1 6296 . . . 4  |-  F  Fn  On
3 fndm 5197 . . . 4  |-  ( F  Fn  On  ->  dom  F  =  On )
42, 3ax-mp 10 . . 3  |-  dom  F  =  On
54eleq2i 2317 . 2  |-  ( A  e.  dom  F  <->  A  e.  On )
61tfr2a 6294 . 2  |-  ( A  e.  dom  F  -> 
( F `  A
)  =  ( G `
 ( F  |`  A ) ) )
75, 6sylbir 206 1  |-  ( A  e.  On  ->  ( F `  A )  =  ( G `  ( F  |`  A ) ) )
Colors of variables: wff set class
Syntax hints:    -> wi 6    = wceq 1619    e. wcel 1621   Oncon0 4282   dom cdm 4577    |` cres 4579    Fn wfn 4584   ` cfv 4589  recscrecs 6270
This theorem is referenced by:  tfr3  6298  recsval  6300  rdgval  6316  dfac8alem  7537  dfac12lem1  7650  zorn2lem1  8004  ttukeylem3  8019
This theorem was proved from axioms:  ax-1 7  ax-2 8  ax-3 9  ax-mp 10  ax-5 1533  ax-6 1534  ax-7 1535  ax-gen 1536  ax-8 1623  ax-11 1624  ax-13 1625  ax-14 1626  ax-17 1628  ax-12o 1664  ax-10 1678  ax-9 1684  ax-4 1692  ax-16 1926  ax-ext 2234  ax-rep 4025  ax-sep 4035  ax-nul 4043  ax-pr 4105  ax-un 4400
This theorem depends on definitions:  df-bi 179  df-or 361  df-an 362  df-3or 940  df-3an 941  df-tru 1315  df-ex 1538  df-nf 1540  df-sb 1883  df-eu 2118  df-mo 2119  df-clab 2240  df-cleq 2246  df-clel 2249  df-nfc 2374  df-ne 2414  df-ral 2511  df-rex 2512  df-reu 2513  df-rab 2514  df-v 2727  df-sbc 2920  df-csb 3007  df-dif 3078  df-un 3080  df-in 3082  df-ss 3086  df-pss 3088  df-nul 3360  df-if 3468  df-sn 3547  df-pr 3548  df-tp 3549  df-op 3550  df-uni 3725  df-iun 3802  df-br 3918  df-opab 3972  df-mpt 3973  df-tr 4008  df-eprel 4195  df-id 4199  df-po 4204  df-so 4205  df-fr 4242  df-we 4244  df-ord 4285  df-on 4286  df-suc 4288  df-xp 4591  df-rel 4592  df-cnv 4593  df-co 4594  df-dm 4595  df-rn 4596  df-res 4597  df-ima 4598  df-fun 4599  df-fn 4600  df-f 4601  df-f1 4602  df-fo 4603  df-f1o 4604  df-fv 4605  df-recs 6271
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