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Theorem ssintub 3759
Description: Subclass of the least upper bound. (Contributed by NM, 8-Aug-2000.)
Assertion
Ref Expression
ssintub  |-  A  C_  |^|
{ x  e.  B  |  A  C_  x }
Distinct variable groups:    x, A    x, B

Proof of Theorem ssintub
Dummy variable  y is distinct from all other variables.
StepHypRef Expression
1 ssint 3757 . 2  |-  ( A 
C_  |^| { x  e.  B  |  A  C_  x }  <->  A. y  e.  {
x  e.  B  |  A  C_  x } A  C_  y )
2 sseq2 3091 . . . 4  |-  ( x  =  y  ->  ( A  C_  x  <->  A  C_  y
) )
32elrab 2813 . . 3  |-  ( y  e.  { x  e.  B  |  A  C_  x }  <->  ( y  e.  B  /\  A  C_  y ) )
43simprbi 273 . 2  |-  ( y  e.  { x  e.  B  |  A  C_  x }  ->  A  C_  y )
51, 4mprgbir 2467 1  |-  A  C_  |^|
{ x  e.  B  |  A  C_  x }
Colors of variables: wff set class
Syntax hints:    e. wcel 1465   {crab 2397    C_ wss 3041   |^|cint 3741
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-ia1 105  ax-ia2 106  ax-ia3 107  ax-io 683  ax-5 1408  ax-7 1409  ax-gen 1410  ax-ie1 1454  ax-ie2 1455  ax-8 1467  ax-10 1468  ax-11 1469  ax-i12 1470  ax-bndl 1471  ax-4 1472  ax-17 1491  ax-i9 1495  ax-ial 1499  ax-i5r 1500  ax-ext 2099
This theorem depends on definitions:  df-bi 116  df-tru 1319  df-nf 1422  df-sb 1721  df-clab 2104  df-cleq 2110  df-clel 2113  df-nfc 2247  df-ral 2398  df-rab 2402  df-v 2662  df-in 3047  df-ss 3054  df-int 3742
This theorem is referenced by:  intmin  3761  sscls  12216
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