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Theorem isfin1-4 8013
Description: A set is I-finite iff every system of subsets contains a minimal subset. (Contributed by Stefan O'Rear, 4-Nov-2014.) (Revised by Mario Carneiro, 17-May-2015.)
Assertion
Ref Expression
isfin1-4  |-  ( A  e.  V  ->  ( A  e.  Fin  <-> [ C.]  Fr  ~P A ) )

Proof of Theorem isfin1-4
Dummy variable  x is distinct from all other variables.
StepHypRef Expression
1 isfin1-3 8012 . 2  |-  ( A  e.  V  ->  ( A  e.  Fin  <->  `' [ C.]  Fr  ~P A ) )
2 eqid 2283 . . . 4  |-  ( x  e.  ~P A  |->  ( A  \  x ) )  =  ( x  e.  ~P A  |->  ( A  \  x ) )
32compssiso 8000 . . 3  |-  ( A  e.  V  ->  (
x  e.  ~P A  |->  ( A  \  x
) )  Isom [ C.]  ,  `' [ C.]  ( ~P A ,  ~P A ) )
4 isofr 5839 . . 3  |-  ( ( x  e.  ~P A  |->  ( A  \  x
) )  Isom [ C.]  ,  `' [ C.]  ( ~P A ,  ~P A )  -> 
( [ C.]  Fr  ~P A 
<->  `' [ C.]  Fr  ~P A
) )
53, 4syl 15 . 2  |-  ( A  e.  V  ->  ( [ C.]  Fr  ~P A  <->  `' [ C.]  Fr  ~P A ) )
61, 5bitr4d 247 1  |-  ( A  e.  V  ->  ( A  e.  Fin  <-> [ C.]  Fr  ~P A ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 176    e. wcel 1684    \ cdif 3149   ~Pcpw 3625    e. cmpt 4077    Fr wfr 4349   `'ccnv 4688    Isom wiso 5256   [ C.] crpss 6276   Fincfn 6863
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1533  ax-5 1544  ax-17 1603  ax-9 1635  ax-8 1643  ax-13 1686  ax-14 1688  ax-6 1703  ax-7 1708  ax-11 1715  ax-12 1866  ax-ext 2264  ax-rep 4131  ax-sep 4141  ax-nul 4149  ax-pow 4188  ax-pr 4214  ax-un 4512
This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-3or 935  df-3an 936  df-tru 1310  df-ex 1529  df-nf 1532  df-sb 1630  df-eu 2147  df-mo 2148  df-clab 2270  df-cleq 2276  df-clel 2279  df-nfc 2408  df-ne 2448  df-ral 2548  df-rex 2549  df-reu 2550  df-rab 2552  df-v 2790  df-sbc 2992  df-csb 3082  df-dif 3155  df-un 3157  df-in 3159  df-ss 3166  df-pss 3168  df-nul 3456  df-if 3566  df-pw 3627  df-sn 3646  df-pr 3647  df-tp 3648  df-op 3649  df-uni 3828  df-int 3863  df-iun 3907  df-br 4024  df-opab 4078  df-mpt 4079  df-tr 4114  df-eprel 4305  df-id 4309  df-po 4314  df-so 4315  df-fr 4352  df-we 4354  df-ord 4395  df-on 4396  df-lim 4397  df-suc 4398  df-om 4657  df-xp 4695  df-rel 4696  df-cnv 4697  df-co 4698  df-dm 4699  df-rn 4700  df-res 4701  df-ima 4702  df-iota 5219  df-fun 5257  df-fn 5258  df-f 5259  df-f1 5260  df-fo 5261  df-f1o 5262  df-fv 5263  df-isom 5264  df-ov 5861  df-oprab 5862  df-mpt2 5863  df-1st 6122  df-2nd 6123  df-rpss 6277  df-recs 6388  df-rdg 6423  df-1o 6479  df-2o 6480  df-oadd 6483  df-er 6660  df-map 6774  df-en 6864  df-dom 6865  df-sdom 6866  df-fin 6867
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