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Theorem onintrab2im 4660
Description: An existence condition which implies an intersection is an ordinal number. (Contributed by Jim Kingdon, 30-Aug-2021.)
Assertion
Ref Expression
onintrab2im  |-  ( E. x  e.  On  ph  ->  |^| { x  e.  On  |  ph }  e.  On )

Proof of Theorem onintrab2im
Dummy variable  y is distinct from all other variables.
StepHypRef Expression
1 ssrab2 3333 . 2  |-  { x  e.  On  |  ph }  C_  On
2 nfrab1 2732 . . . . 5  |-  F/_ x { x  e.  On  |  ph }
32nfcri 2386 . . . 4  |-  F/ x  y  e.  { x  e.  On  |  ph }
43nfex 1690 . . 3  |-  F/ x E. y  y  e.  { x  e.  On  |  ph }
5 rabid 2727 . . . . 5  |-  ( x  e.  { x  e.  On  |  ph }  <->  ( x  e.  On  /\  ph ) )
6 elex2 2838 . . . . 5  |-  ( x  e.  { x  e.  On  |  ph }  ->  E. y  y  e. 
{ x  e.  On  |  ph } )
75, 6sylbir 135 . . . 4  |-  ( ( x  e.  On  /\  ph )  ->  E. y 
y  e.  { x  e.  On  |  ph }
)
87ex 115 . . 3  |-  ( x  e.  On  ->  ( ph  ->  E. y  y  e. 
{ x  e.  On  |  ph } ) )
94, 8rexlimi 2661 . 2  |-  ( E. x  e.  On  ph  ->  E. y  y  e. 
{ x  e.  On  |  ph } )
10 onintonm 4659 . 2  |-  ( ( { x  e.  On  |  ph }  C_  On  /\ 
E. y  y  e. 
{ x  e.  On  |  ph } )  ->  |^| { x  e.  On  |  ph }  e.  On )
111, 9, 10sylancr 418 1  |-  ( E. x  e.  On  ph  ->  |^| { x  e.  On  |  ph }  e.  On )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104   E.wex 1545    e. wcel 2209   E.wrex 2529   {crab 2532    C_ wss 3220   |^|cint 3965   Oncon0 4503
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-io 721  ax-5 1500  ax-7 1501  ax-gen 1502  ax-ie1 1546  ax-ie2 1547  ax-8 1557  ax-10 1558  ax-11 1559  ax-i12 1560  ax-bndl 1562  ax-4 1563  ax-17 1579  ax-i9 1583  ax-ial 1587  ax-i5r 1588  ax-14 2212  ax-ext 2220  ax-sep 4244  ax-pow 4306  ax-pr 4341  ax-un 4573
This theorem depends on definitions:  df-bi 117  df-3an 1011  df-tru 1405  df-nf 1514  df-sb 1816  df-clab 2225  df-cleq 2231  df-clel 2234  df-nfc 2381  df-ral 2533  df-rex 2534  df-rab 2537  df-v 2823  df-un 3224  df-in 3226  df-ss 3233  df-pw 3687  df-sn 3711  df-pr 3712  df-uni 3931  df-int 3966  df-tr 4225  df-iord 4506  df-on 4508  df-suc 4511
This theorem is referenced by:  cardcl  7516
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