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Theorem xpmlem 5149
Description: The cross product of inhabited classes is inhabited. (Contributed by Jim Kingdon, 11-Dec-2018.)
Assertion
Ref Expression
xpmlem  |-  ( ( E. x  x  e.  A  /\  E. y 
y  e.  B )  <->  E. z  z  e.  ( A  X.  B
) )
Distinct variable groups:    x, y, z, A    x, B, y, z

Proof of Theorem xpmlem
StepHypRef Expression
1 eeanv 1983 . . 3  |-  ( E. x E. y ( x  e.  A  /\  y  e.  B )  <->  ( E. x  x  e.  A  /\  E. y 
y  e.  B ) )
2 vex 2802 . . . . . 6  |-  x  e. 
_V
3 vex 2802 . . . . . 6  |-  y  e. 
_V
42, 3opex 4315 . . . . 5  |-  <. x ,  y >.  e.  _V
5 eleq1 2292 . . . . . 6  |-  ( z  =  <. x ,  y
>.  ->  ( z  e.  ( A  X.  B
)  <->  <. x ,  y
>.  e.  ( A  X.  B ) ) )
6 opelxp 4749 . . . . . 6  |-  ( <.
x ,  y >.  e.  ( A  X.  B
)  <->  ( x  e.  A  /\  y  e.  B ) )
75, 6bitrdi 196 . . . . 5  |-  ( z  =  <. x ,  y
>.  ->  ( z  e.  ( A  X.  B
)  <->  ( x  e.  A  /\  y  e.  B ) ) )
84, 7spcev 2898 . . . 4  |-  ( ( x  e.  A  /\  y  e.  B )  ->  E. z  z  e.  ( A  X.  B
) )
98exlimivv 1943 . . 3  |-  ( E. x E. y ( x  e.  A  /\  y  e.  B )  ->  E. z  z  e.  ( A  X.  B
) )
101, 9sylbir 135 . 2  |-  ( ( E. x  x  e.  A  /\  E. y 
y  e.  B )  ->  E. z  z  e.  ( A  X.  B
) )
11 elxp 4736 . . . . 5  |-  ( z  e.  ( A  X.  B )  <->  E. x E. y ( z  = 
<. x ,  y >.  /\  ( x  e.  A  /\  y  e.  B
) ) )
12 simpr 110 . . . . . 6  |-  ( ( z  =  <. x ,  y >.  /\  (
x  e.  A  /\  y  e.  B )
)  ->  ( x  e.  A  /\  y  e.  B ) )
13122eximi 1647 . . . . 5  |-  ( E. x E. y ( z  =  <. x ,  y >.  /\  (
x  e.  A  /\  y  e.  B )
)  ->  E. x E. y ( x  e.  A  /\  y  e.  B ) )
1411, 13sylbi 121 . . . 4  |-  ( z  e.  ( A  X.  B )  ->  E. x E. y ( x  e.  A  /\  y  e.  B ) )
1514exlimiv 1644 . . 3  |-  ( E. z  z  e.  ( A  X.  B )  ->  E. x E. y
( x  e.  A  /\  y  e.  B
) )
1615, 1sylib 122 . 2  |-  ( E. z  z  e.  ( A  X.  B )  ->  ( E. x  x  e.  A  /\  E. y  y  e.  B
) )
1710, 16impbii 126 1  |-  ( ( E. x  x  e.  A  /\  E. y 
y  e.  B )  <->  E. z  z  e.  ( A  X.  B
) )
Colors of variables: wff set class
Syntax hints:    /\ wa 104    <-> wb 105    = wceq 1395   E.wex 1538    e. wcel 2200   <.cop 3669    X. cxp 4717
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 714  ax-5 1493  ax-7 1494  ax-gen 1495  ax-ie1 1539  ax-ie2 1540  ax-8 1550  ax-10 1551  ax-11 1552  ax-i12 1553  ax-bndl 1555  ax-4 1556  ax-17 1572  ax-i9 1576  ax-ial 1580  ax-i5r 1581  ax-14 2203  ax-ext 2211  ax-sep 4202  ax-pow 4258  ax-pr 4293
This theorem depends on definitions:  df-bi 117  df-3an 1004  df-tru 1398  df-nf 1507  df-sb 1809  df-clab 2216  df-cleq 2222  df-clel 2225  df-nfc 2361  df-ral 2513  df-rex 2514  df-v 2801  df-un 3201  df-in 3203  df-ss 3210  df-pw 3651  df-sn 3672  df-pr 3673  df-op 3675  df-opab 4146  df-xp 4725
This theorem is referenced by:  xpm  5150
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