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Theorem opabn0 4477
Description: Non-empty ordered pair class abstraction. (Contributed by NM, 10-Oct-2007.)
Assertion
Ref Expression
opabn0  |-  ( {
<. x ,  y >.  |  ph }  =/=  (/)  <->  E. x E. y ph )

Proof of Theorem opabn0
Dummy variable  z is distinct from all other variables.
StepHypRef Expression
1 n0 3629 . 2  |-  ( {
<. x ,  y >.  |  ph }  =/=  (/)  <->  E. z 
z  e.  { <. x ,  y >.  |  ph } )
2 elopab 4454 . . . 4  |-  ( z  e.  { <. x ,  y >.  |  ph } 
<->  E. x E. y
( z  =  <. x ,  y >.  /\  ph ) )
32exbii 1592 . . 3  |-  ( E. z  z  e.  { <. x ,  y >.  |  ph }  <->  E. z E. x E. y ( z  =  <. x ,  y >.  /\  ph ) )
4 exrot3 1759 . . . 4  |-  ( E. z E. x E. y ( z  = 
<. x ,  y >.  /\  ph )  <->  E. x E. y E. z ( z  =  <. x ,  y >.  /\  ph ) )
5 opex 4419 . . . . . . 7  |-  <. x ,  y >.  e.  _V
65isseti 2954 . . . . . 6  |-  E. z 
z  =  <. x ,  y >.
7 19.41v 1924 . . . . . 6  |-  ( E. z ( z  = 
<. x ,  y >.  /\  ph )  <->  ( E. z  z  =  <. x ,  y >.  /\  ph ) )
86, 7mpbiran 885 . . . . 5  |-  ( E. z ( z  = 
<. x ,  y >.  /\  ph )  <->  ph )
982exbii 1593 . . . 4  |-  ( E. x E. y E. z ( z  = 
<. x ,  y >.  /\  ph )  <->  E. x E. y ph )
104, 9bitri 241 . . 3  |-  ( E. z E. x E. y ( z  = 
<. x ,  y >.  /\  ph )  <->  E. x E. y ph )
113, 10bitri 241 . 2  |-  ( E. z  z  e.  { <. x ,  y >.  |  ph }  <->  E. x E. y ph )
121, 11bitri 241 1  |-  ( {
<. x ,  y >.  |  ph }  =/=  (/)  <->  E. x E. y ph )
Colors of variables: wff set class
Syntax hints:    <-> wb 177    /\ wa 359   E.wex 1550    = wceq 1652    e. wcel 1725    =/= wne 2598   (/)c0 3620   <.cop 3809   {copab 4257
This theorem is referenced by:  dvdsrval  15738  thlle  16912  bcthlem5  19269  lgsquadlem3  21128
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-14 1729  ax-6 1744  ax-7 1749  ax-11 1761  ax-12 1950  ax-ext 2416  ax-sep 4322  ax-nul 4330  ax-pr 4395
This theorem depends on definitions:  df-bi 178  df-or 360  df-an 361  df-3an 938  df-tru 1328  df-ex 1551  df-nf 1554  df-sb 1659  df-clab 2422  df-cleq 2428  df-clel 2431  df-nfc 2560  df-ne 2600  df-v 2950  df-dif 3315  df-un 3317  df-in 3319  df-ss 3326  df-nul 3621  df-if 3732  df-sn 3812  df-pr 3813  df-op 3815  df-opab 4259
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