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Theorem xpen 6792
Description: Equinumerosity law for Cartesian product. Proposition 4.22(b) of [Mendelson] p. 254. (Contributed by NM, 24-Jul-2004.)
Assertion
Ref Expression
xpen  |-  ( ( A  ~~  B  /\  C  ~~  D )  -> 
( A  X.  C
)  ~~  ( B  X.  D ) )

Proof of Theorem xpen
Dummy variables  f  g  x  y are mutually distinct and distinct from all other variables.
StepHypRef Expression
1 bren 6694 . . . 4  |-  ( A 
~~  B  <->  E. f 
f : A -1-1-onto-> B )
21biimpi 119 . . 3  |-  ( A 
~~  B  ->  E. f 
f : A -1-1-onto-> B )
32adantr 274 . 2  |-  ( ( A  ~~  B  /\  C  ~~  D )  ->  E. f  f : A
-1-1-onto-> B )
4 bren 6694 . . . . 5  |-  ( C 
~~  D  <->  E. g 
g : C -1-1-onto-> D )
54biimpi 119 . . . 4  |-  ( C 
~~  D  ->  E. g 
g : C -1-1-onto-> D )
65ad2antlr 481 . . 3  |-  ( ( ( A  ~~  B  /\  C  ~~  D )  /\  f : A -1-1-onto-> B
)  ->  E. g 
g : C -1-1-onto-> D )
7 relen 6691 . . . . . . 7  |-  Rel  ~~
87brrelex1i 4631 . . . . . 6  |-  ( A 
~~  B  ->  A  e.  _V )
97brrelex1i 4631 . . . . . 6  |-  ( C 
~~  D  ->  C  e.  _V )
10 xpexg 4702 . . . . . 6  |-  ( ( A  e.  _V  /\  C  e.  _V )  ->  ( A  X.  C
)  e.  _V )
118, 9, 10syl2an 287 . . . . 5  |-  ( ( A  ~~  B  /\  C  ~~  D )  -> 
( A  X.  C
)  e.  _V )
1211ad2antrr 480 . . . 4  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  ( A  X.  C )  e. 
_V )
13 simplr 520 . . . . . 6  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  f : A -1-1-onto-> B )
14 f1ofn 5417 . . . . . . . 8  |-  ( f : A -1-1-onto-> B  ->  f  Fn  A )
15 dffn5im 5516 . . . . . . . 8  |-  ( f  Fn  A  ->  f  =  ( x  e.  A  |->  ( f `  x ) ) )
1614, 15syl 14 . . . . . . 7  |-  ( f : A -1-1-onto-> B  ->  f  =  ( x  e.  A  |->  ( f `  x
) ) )
17 f1oeq1 5405 . . . . . . 7  |-  ( f  =  ( x  e.  A  |->  ( f `  x ) )  -> 
( f : A -1-1-onto-> B  <->  ( x  e.  A  |->  ( f `  x ) ) : A -1-1-onto-> B ) )
1813, 16, 173syl 17 . . . . . 6  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  (
f : A -1-1-onto-> B  <->  ( x  e.  A  |->  ( f `
 x ) ) : A -1-1-onto-> B ) )
1913, 18mpbid 146 . . . . 5  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  (
x  e.  A  |->  ( f `  x ) ) : A -1-1-onto-> B )
20 simpr 109 . . . . . 6  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  g : C -1-1-onto-> D )
21 f1ofn 5417 . . . . . . . 8  |-  ( g : C -1-1-onto-> D  ->  g  Fn  C )
22 dffn5im 5516 . . . . . . . 8  |-  ( g  Fn  C  ->  g  =  ( y  e.  C  |->  ( g `  y ) ) )
2321, 22syl 14 . . . . . . 7  |-  ( g : C -1-1-onto-> D  ->  g  =  ( y  e.  C  |->  ( g `  y
) ) )
24 f1oeq1 5405 . . . . . . 7  |-  ( g  =  ( y  e.  C  |->  ( g `  y ) )  -> 
( g : C -1-1-onto-> D  <->  ( y  e.  C  |->  ( g `  y ) ) : C -1-1-onto-> D ) )
2520, 23, 243syl 17 . . . . . 6  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  (
g : C -1-1-onto-> D  <->  ( y  e.  C  |->  ( g `
 y ) ) : C -1-1-onto-> D ) )
2620, 25mpbid 146 . . . . 5  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  (
y  e.  C  |->  ( g `  y ) ) : C -1-1-onto-> D )
2719, 26xpf1o 6791 . . . 4  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  (
x  e.  A , 
y  e.  C  |->  <.
( f `  x
) ,  ( g `
 y ) >.
) : ( A  X.  C ) -1-1-onto-> ( B  X.  D ) )
28 f1oeng 6704 . . . 4  |-  ( ( ( A  X.  C
)  e.  _V  /\  ( x  e.  A ,  y  e.  C  |-> 
<. ( f `  x
) ,  ( g `
 y ) >.
) : ( A  X.  C ) -1-1-onto-> ( B  X.  D ) )  ->  ( A  X.  C )  ~~  ( B  X.  D ) )
2912, 27, 28syl2anc 409 . . 3  |-  ( ( ( ( A  ~~  B  /\  C  ~~  D
)  /\  f : A
-1-1-onto-> B )  /\  g : C -1-1-onto-> D )  ->  ( A  X.  C )  ~~  ( B  X.  D
) )
306, 29exlimddv 1878 . 2  |-  ( ( ( A  ~~  B  /\  C  ~~  D )  /\  f : A -1-1-onto-> B
)  ->  ( A  X.  C )  ~~  ( B  X.  D ) )
313, 30exlimddv 1878 1  |-  ( ( A  ~~  B  /\  C  ~~  D )  -> 
( A  X.  C
)  ~~  ( B  X.  D ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103    <-> wb 104    = wceq 1335   E.wex 1472    e. wcel 2128   _Vcvv 2712   <.cop 3564   class class class wbr 3967    |-> cmpt 4027    X. cxp 4586    Fn wfn 5167   -1-1-onto->wf1o 5171   ` cfv 5172    e. cmpo 5828    ~~ cen 6685
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 699  ax-5 1427  ax-7 1428  ax-gen 1429  ax-ie1 1473  ax-ie2 1474  ax-8 1484  ax-10 1485  ax-11 1486  ax-i12 1487  ax-bndl 1489  ax-4 1490  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-13 2130  ax-14 2131  ax-ext 2139  ax-coll 4081  ax-sep 4084  ax-pow 4137  ax-pr 4171  ax-un 4395
This theorem depends on definitions:  df-bi 116  df-3an 965  df-tru 1338  df-nf 1441  df-sb 1743  df-eu 2009  df-mo 2010  df-clab 2144  df-cleq 2150  df-clel 2153  df-nfc 2288  df-ral 2440  df-rex 2441  df-reu 2442  df-rab 2444  df-v 2714  df-sbc 2938  df-csb 3032  df-un 3106  df-in 3108  df-ss 3115  df-pw 3546  df-sn 3567  df-pr 3568  df-op 3570  df-uni 3775  df-iun 3853  df-br 3968  df-opab 4028  df-mpt 4029  df-id 4255  df-xp 4594  df-rel 4595  df-cnv 4596  df-co 4597  df-dm 4598  df-rn 4599  df-res 4600  df-ima 4601  df-iota 5137  df-fun 5174  df-fn 5175  df-f 5176  df-f1 5177  df-fo 5178  df-f1o 5179  df-fv 5180  df-oprab 5830  df-mpo 5831  df-1st 6090  df-2nd 6091  df-en 6688
This theorem is referenced by:  xpdjuen  7155  xpnnen  12193  xpomen  12194  qnnen  12230
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