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Theorem xpmlem 5183
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 1986 . . 3  |-  ( E. x E. y ( x  e.  A  /\  y  e.  B )  <->  ( E. x  x  e.  A  /\  E. y 
y  e.  B ) )
2 vex 2816 . . . . . 6  |-  x  e. 
_V
3 vex 2816 . . . . . 6  |-  y  e. 
_V
42, 3opex 4345 . . . . 5  |-  <. x ,  y >.  e.  _V
5 eleq1 2295 . . . . . 6  |-  ( z  =  <. x ,  y
>.  ->  ( z  e.  ( A  X.  B
)  <->  <. x ,  y
>.  e.  ( A  X.  B ) ) )
6 opelxp 4779 . . . . . 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 2912 . . . 4  |-  ( ( x  e.  A  /\  y  e.  B )  ->  E. z  z  e.  ( A  X.  B
) )
98exlimivv 1946 . . 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 4766 . . . . 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 1650 . . . . 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 1647 . . 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 1398   E.wex 1541    e. wcel 2203   <.cop 3692    X. cxp 4747
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 717  ax-5 1496  ax-7 1497  ax-gen 1498  ax-ie1 1542  ax-ie2 1543  ax-8 1553  ax-10 1554  ax-11 1555  ax-i12 1556  ax-bndl 1558  ax-4 1559  ax-17 1575  ax-i9 1579  ax-ial 1583  ax-i5r 1584  ax-14 2206  ax-ext 2214  ax-sep 4228  ax-pow 4287  ax-pr 4322
This theorem depends on definitions:  df-bi 117  df-3an 1007  df-tru 1401  df-nf 1510  df-sb 1812  df-clab 2219  df-cleq 2225  df-clel 2228  df-nfc 2373  df-ral 2525  df-rex 2526  df-v 2815  df-un 3215  df-in 3217  df-ss 3224  df-pw 3671  df-sn 3695  df-pr 3696  df-op 3698  df-opab 4172  df-xp 4755
This theorem is referenced by:  xpm  5184
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