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Theorem dmxpm 4848
Description: The domain of a cross product. Part of Theorem 3.13(x) of [Monk1] p. 37. (Contributed by NM, 28-Jul-1995.) (Proof shortened by Andrew Salmon, 27-Aug-2011.)
Assertion
Ref Expression
dmxpm  |-  ( E. x  x  e.  B  ->  dom  ( A  X.  B )  =  A )
Distinct variable group:    x, B
Allowed substitution hint:    A( x)

Proof of Theorem dmxpm
Dummy variables  y  z are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 eleq1 2240 . . 3  |-  ( x  =  z  ->  (
x  e.  B  <->  z  e.  B ) )
21cbvexv 1918 . 2  |-  ( E. x  x  e.  B  <->  E. z  z  e.  B
)
3 df-xp 4633 . . . 4  |-  ( A  X.  B )  =  { <. y ,  z
>.  |  ( y  e.  A  /\  z  e.  B ) }
43dmeqi 4829 . . 3  |-  dom  ( A  X.  B )  =  dom  { <. y ,  z >.  |  ( y  e.  A  /\  z  e.  B ) }
5 id 19 . . . . 5  |-  ( E. z  z  e.  B  ->  E. z  z  e.  B )
65ralrimivw 2551 . . . 4  |-  ( E. z  z  e.  B  ->  A. y  e.  A  E. z  z  e.  B )
7 dmopab3 4841 . . . 4  |-  ( A. y  e.  A  E. z  z  e.  B  <->  dom 
{ <. y ,  z
>.  |  ( y  e.  A  /\  z  e.  B ) }  =  A )
86, 7sylib 122 . . 3  |-  ( E. z  z  e.  B  ->  dom  { <. y ,  z >.  |  ( y  e.  A  /\  z  e.  B ) }  =  A )
94, 8eqtrid 2222 . 2  |-  ( E. z  z  e.  B  ->  dom  ( A  X.  B )  =  A )
102, 9sylbi 121 1  |-  ( E. x  x  e.  B  ->  dom  ( A  X.  B )  =  A )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 104    = wceq 1353   E.wex 1492    e. wcel 2148   A.wral 2455   {copab 4064    X. cxp 4625   dom cdm 4627
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 709  ax-5 1447  ax-7 1448  ax-gen 1449  ax-ie1 1493  ax-ie2 1494  ax-8 1504  ax-10 1505  ax-11 1506  ax-i12 1507  ax-bndl 1509  ax-4 1510  ax-17 1526  ax-i9 1530  ax-ial 1534  ax-i5r 1535  ax-14 2151  ax-ext 2159  ax-sep 4122  ax-pow 4175  ax-pr 4210
This theorem depends on definitions:  df-bi 117  df-3an 980  df-tru 1356  df-nf 1461  df-sb 1763  df-eu 2029  df-mo 2030  df-clab 2164  df-cleq 2170  df-clel 2173  df-nfc 2308  df-ral 2460  df-v 2740  df-un 3134  df-in 3136  df-ss 3143  df-pw 3578  df-sn 3599  df-pr 3600  df-op 3602  df-br 4005  df-opab 4066  df-xp 4633  df-dm 4637
This theorem is referenced by:  rnxpm  5059  ssxpbm  5065  ssxp1  5066  xpexr2m  5071  relrelss  5156  unixpm  5165  exmidfodomrlemim  7200  imasaddfnlemg  12735
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