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Theorem nnregexmid 4654
Description: If inhabited sets of natural numbers always have minimal elements, excluded middle follows. The argument is essentially the same as regexmid 4568 and the larger lesson is that although natural numbers may behave "non-constructively" even in a constructive set theory (for example see nndceq 6554 or nntri3or 6548), sets of natural numbers are a different animal. (Contributed by Jim Kingdon, 6-Sep-2019.)
Hypothesis
Ref Expression
nnregexmid.1  |-  ( ( x  C_  om  /\  E. y  y  e.  x
)  ->  E. y
( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
) )
Assertion
Ref Expression
nnregexmid  |-  ( ph  \/  -.  ph )
Distinct variable group:    ph, x, y, z

Proof of Theorem nnregexmid
Dummy variable  w is distinct from all other variables.
StepHypRef Expression
1 ssrab2 3265 . . . 4  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  {
(/) ,  { (/) } }
2 peano1 4627 . . . . 5  |-  (/)  e.  om
3 suc0 4443 . . . . . 6  |-  suc  (/)  =  { (/)
}
4 peano2 4628 . . . . . . 7  |-  ( (/)  e.  om  ->  suc  (/)  e.  om )
52, 4ax-mp 5 . . . . . 6  |-  suc  (/)  e.  om
63, 5eqeltrri 2267 . . . . 5  |-  { (/) }  e.  om
7 prssi 3777 . . . . 5  |-  ( (
(/)  e.  om  /\  { (/)
}  e.  om )  ->  { (/) ,  { (/) } }  C_  om )
82, 6, 7mp2an 426 . . . 4  |-  { (/) ,  { (/) } }  C_  om
91, 8sstri 3189 . . 3  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  om
10 eqid 2193 . . . 4  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  =  { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }
1110regexmidlemm 4565 . . 3  |-  E. y 
y  e.  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }
12 pp0ex 4219 . . . . 5  |-  { (/) ,  { (/) } }  e.  _V
1312rabex 4174 . . . 4  |-  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  e.  _V
14 sseq1 3203 . . . . . 6  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( x  C_  om  <->  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  om ) )
15 eleq2 2257 . . . . . . 7  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( y  e.  x  <->  y  e.  { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) } ) )
1615exbidv 1836 . . . . . 6  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( E. y  y  e.  x  <->  E. y  y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) )
1714, 16anbi12d 473 . . . . 5  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( x  C_  om  /\  E. y  y  e.  x
)  <->  ( { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  C_  om 
/\  E. y  y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
18 eleq2 2257 . . . . . . . . . 10  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( z  e.  x  <->  z  e.  { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) } ) )
1918notbid 668 . . . . . . . . 9  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( -.  z  e.  x  <->  -.  z  e.  { w  e.  { (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) } ) )
2019imbi2d 230 . . . . . . . 8  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( z  e.  y  ->  -.  z  e.  x )  <->  ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
2120albidv 1835 . . . . . . 7  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( A. z ( z  e.  y  ->  -.  z  e.  x )  <->  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
2215, 21anbi12d 473 . . . . . 6  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
)  <->  ( y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) ) )
2322exbidv 1836 . . . . 5  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( E. y ( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x ) )  <->  E. y
( y  e.  {
w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) ) )
2417, 23imbi12d 234 . . . 4  |-  ( x  =  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  ->  ( ( ( x  C_  om 
/\  E. y  y  e.  x )  ->  E. y
( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
) )  <->  ( ( { w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }  C_  om  /\  E. y  y  e.  {
w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) } )  ->  E. y ( y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) ) ) )
25 nnregexmid.1 . . . 4  |-  ( ( x  C_  om  /\  E. y  y  e.  x
)  ->  E. y
( y  e.  x  /\  A. z ( z  e.  y  ->  -.  z  e.  x )
) )
2613, 24, 25vtocl 2815 . . 3  |-  ( ( { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  C_  om 
/\  E. y  y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } )  ->  E. y ( y  e.  { w  e. 
{ (/) ,  { (/) } }  |  ( w  =  { (/) }  \/  ( w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) ) )
279, 11, 26mp2an 426 . 2  |-  E. y
( y  e.  {
w  e.  { (/) ,  { (/) } }  | 
( w  =  { (/)
}  \/  ( w  =  (/)  /\  ph )
) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) )
2810regexmidlem1 4566 . 2  |-  ( E. y ( y  e. 
{ w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) }  /\  A. z ( z  e.  y  ->  -.  z  e.  { w  e.  { (/)
,  { (/) } }  |  ( w  =  { (/) }  \/  (
w  =  (/)  /\  ph ) ) } ) )  ->  ( ph  \/  -.  ph ) )
2927, 28ax-mp 5 1  |-  ( ph  \/  -.  ph )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 104    \/ wo 709   A.wal 1362    = wceq 1364   E.wex 1503    e. wcel 2164   {crab 2476    C_ wss 3154   (/)c0 3447   {csn 3619   {cpr 3620   suc csuc 4397   omcom 4623
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 106  ax-ia2 107  ax-ia3 108  ax-in1 615  ax-in2 616  ax-io 710  ax-5 1458  ax-7 1459  ax-gen 1460  ax-ie1 1504  ax-ie2 1505  ax-8 1515  ax-10 1516  ax-11 1517  ax-i12 1518  ax-bndl 1520  ax-4 1521  ax-17 1537  ax-i9 1541  ax-ial 1545  ax-i5r 1546  ax-13 2166  ax-14 2167  ax-ext 2175  ax-sep 4148  ax-nul 4156  ax-pow 4204  ax-pr 4239  ax-un 4465
This theorem depends on definitions:  df-bi 117  df-3an 982  df-tru 1367  df-nf 1472  df-sb 1774  df-clab 2180  df-cleq 2186  df-clel 2189  df-nfc 2325  df-ral 2477  df-rex 2478  df-rab 2481  df-v 2762  df-dif 3156  df-un 3158  df-in 3160  df-ss 3167  df-nul 3448  df-pw 3604  df-sn 3625  df-pr 3626  df-uni 3837  df-int 3872  df-suc 4403  df-iom 4624
This theorem is referenced by: (None)
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