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Theorem zfregs 7942
Description: The strong form of the Axiom of Regularity, which does not require that  A be a set. Axiom 6' of [TakeutiZaring] p. 21. See also epfrs 7941. (Contributed by NM, 17-Sep-2003.)
Assertion
Ref Expression
zfregs  |-  ( A  =/=  (/)  ->  E. x  e.  A  ( x  i^i  A )  =  (/) )
Distinct variable group:    x, A

Proof of Theorem zfregs
StepHypRef Expression
1 zfregfr 7808 . 2  |-  _E  Fr  A
2 epfrs 7941 . 2  |-  ( (  _E  Fr  A  /\  A  =/=  (/) )  ->  E. x  e.  A  ( x  i^i  A )  =  (/) )
31, 2mpan 665 1  |-  ( A  =/=  (/)  ->  E. x  e.  A  ( x  i^i  A )  =  (/) )
Colors of variables: wff setvar class
Syntax hints:    -> wi 4    = wceq 1364    =/= wne 2598   E.wrex 2708    i^i cin 3317   (/)c0 3627    _E cep 4619    Fr wfr 4665
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1596  ax-4 1607  ax-5 1671  ax-6 1709  ax-7 1729  ax-8 1759  ax-9 1761  ax-10 1776  ax-11 1781  ax-12 1793  ax-13 1944  ax-ext 2416  ax-rep 4393  ax-sep 4403  ax-nul 4411  ax-pow 4460  ax-pr 4521  ax-un 6363  ax-reg 7797  ax-inf2 7837
This theorem depends on definitions:  df-bi 185  df-or 370  df-an 371  df-3or 961  df-3an 962  df-tru 1367  df-ex 1592  df-nf 1595  df-sb 1702  df-eu 2260  df-mo 2261  df-clab 2422  df-cleq 2428  df-clel 2431  df-nfc 2560  df-ne 2600  df-ral 2712  df-rex 2713  df-reu 2714  df-rab 2716  df-v 2966  df-sbc 3178  df-csb 3279  df-dif 3321  df-un 3323  df-in 3325  df-ss 3332  df-pss 3334  df-nul 3628  df-if 3782  df-pw 3852  df-sn 3868  df-pr 3870  df-tp 3872  df-op 3874  df-uni 4082  df-iun 4163  df-br 4283  df-opab 4341  df-mpt 4342  df-tr 4376  df-eprel 4621  df-id 4625  df-po 4630  df-so 4631  df-fr 4668  df-we 4670  df-ord 4711  df-on 4712  df-lim 4713  df-suc 4714  df-xp 4835  df-rel 4836  df-cnv 4837  df-co 4838  df-dm 4839  df-rn 4840  df-res 4841  df-ima 4842  df-iota 5371  df-fun 5410  df-fn 5411  df-f 5412  df-f1 5413  df-fo 5414  df-f1o 5415  df-fv 5416  df-om 6468  df-recs 6820  df-rdg 6854
This theorem is referenced by:  zfregs2  7943  setind  7944  zfregs2VD  31319
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