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Theorem isfiniteg 7353
Description: A set is finite iff it is strictly dominated by the class of natural number. Theorem 42 of [Suppes] p. 151. In order to avoid the Axiom of infinity, we include it as a hypothesis. (Contributed by NM, 3-Nov-2002.) (Revised by Mario Carneiro, 27-Apr-2015.)
Assertion
Ref Expression
isfiniteg  |-  ( om  e.  _V  ->  ( A  e.  Fin  <->  A  ~<  om ) )

Proof of Theorem isfiniteg
Dummy variable  x is distinct from all other variables.
StepHypRef Expression
1 isfi 7117 . . 3  |-  ( A  e.  Fin  <->  E. x  e.  om  A  ~~  x
)
2 nnsdomg 7352 . . . . 5  |-  ( ( om  e.  _V  /\  x  e.  om )  ->  x  ~<  om )
3 sdomen1 7237 . . . . 5  |-  ( A 
~~  x  ->  ( A  ~<  om  <->  x  ~<  om )
)
42, 3syl5ibrcom 214 . . . 4  |-  ( ( om  e.  _V  /\  x  e.  om )  ->  ( A  ~~  x  ->  A  ~<  om )
)
54rexlimdva 2817 . . 3  |-  ( om  e.  _V  ->  ( E. x  e.  om  A  ~~  x  ->  A  ~<  om ) )
61, 5syl5bi 209 . 2  |-  ( om  e.  _V  ->  ( A  e.  Fin  ->  A  ~<  om ) )
7 isfinite2 7351 . 2  |-  ( A 
~<  om  ->  A  e.  Fin )
86, 7impbid1 195 1  |-  ( om  e.  _V  ->  ( A  e.  Fin  <->  A  ~<  om ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 177    /\ wa 359    e. wcel 1725   E.wrex 2693   _Vcvv 2943   class class class wbr 4199   omcom 4831    ~~ cen 7092    ~< csdm 7094   Fincfn 7095
This theorem is referenced by:  unfi2  7362  unifi2  7382  isfinite  7591  axcclem  8321
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1555  ax-5 1566  ax-17 1626  ax-9 1666  ax-8 1687  ax-13 1727  ax-14 1729  ax-6 1744  ax-7 1749  ax-11 1761  ax-12 1950  ax-ext 2411  ax-sep 4317  ax-nul 4325  ax-pow 4364  ax-pr 4390  ax-un 4687
This theorem depends on definitions:  df-bi 178  df-or 360  df-an 361  df-3or 937  df-3an 938  df-tru 1328  df-ex 1551  df-nf 1554  df-sb 1659  df-eu 2284  df-mo 2285  df-clab 2417  df-cleq 2423  df-clel 2426  df-nfc 2555  df-ne 2595  df-ral 2697  df-rex 2698  df-reu 2699  df-rab 2701  df-v 2945  df-sbc 3149  df-csb 3239  df-dif 3310  df-un 3312  df-in 3314  df-ss 3321  df-pss 3323  df-nul 3616  df-if 3727  df-pw 3788  df-sn 3807  df-pr 3808  df-tp 3809  df-op 3810  df-uni 4003  df-int 4038  df-iun 4082  df-br 4200  df-opab 4254  df-mpt 4255  df-tr 4290  df-eprel 4481  df-id 4485  df-po 4490  df-so 4491  df-fr 4528  df-we 4530  df-ord 4571  df-on 4572  df-lim 4573  df-suc 4574  df-om 4832  df-xp 4870  df-rel 4871  df-cnv 4872  df-co 4873  df-dm 4874  df-rn 4875  df-res 4876  df-ima 4877  df-iota 5404  df-fun 5442  df-fn 5443  df-f 5444  df-f1 5445  df-fo 5446  df-f1o 5447  df-fv 5448  df-recs 6619  df-rdg 6654  df-er 6891  df-en 7096  df-dom 7097  df-sdom 7098  df-fin 7099
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