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Theorem uniiunlem 3056
Description: A subset relationship useful for converting union to indexed union using dfiun2 or dfiun2g and intersection to indexed intersection using dfiin2 . (Contributed by NM, 5-Oct-2006.) (Proof shortened by Mario Carneiro, 26-Sep-2015.)
Assertion
Ref Expression
uniiunlem  |-  ( A. x  e.  A  B  e.  D  ->  ( A. x  e.  A  B  e.  C  <->  { y  |  E. x  e.  A  y  =  B }  C_  C
) )
Distinct variable groups:    x, y    y, A    y, B    x, C
Allowed substitution hints:    A( x)    B( x)    C( y)    D( x, y)

Proof of Theorem uniiunlem
Dummy variable  z is distinct from all other variables.
StepHypRef Expression
1 eqeq1 2062 . . . . . 6  |-  ( y  =  z  ->  (
y  =  B  <->  z  =  B ) )
21rexbidv 2344 . . . . 5  |-  ( y  =  z  ->  ( E. x  e.  A  y  =  B  <->  E. x  e.  A  z  =  B ) )
32cbvabv 2177 . . . 4  |-  { y  |  E. x  e.  A  y  =  B }  =  { z  |  E. x  e.  A  z  =  B }
43sseq1i 2997 . . 3  |-  ( { y  |  E. x  e.  A  y  =  B }  C_  C  <->  { z  |  E. x  e.  A  z  =  B }  C_  C )
5 r19.23v 2442 . . . . 5  |-  ( A. x  e.  A  (
z  =  B  -> 
z  e.  C )  <-> 
( E. x  e.  A  z  =  B  ->  z  e.  C
) )
65albii 1375 . . . 4  |-  ( A. z A. x  e.  A  ( z  =  B  ->  z  e.  C
)  <->  A. z ( E. x  e.  A  z  =  B  ->  z  e.  C ) )
7 ralcom4 2593 . . . 4  |-  ( A. x  e.  A  A. z ( z  =  B  ->  z  e.  C )  <->  A. z A. x  e.  A  ( z  =  B  ->  z  e.  C
) )
8 abss 3037 . . . 4  |-  ( { z  |  E. x  e.  A  z  =  B }  C_  C  <->  A. z
( E. x  e.  A  z  =  B  ->  z  e.  C
) )
96, 7, 83bitr4i 205 . . 3  |-  ( A. x  e.  A  A. z ( z  =  B  ->  z  e.  C )  <->  { z  |  E. x  e.  A  z  =  B }  C_  C )
104, 9bitr4i 180 . 2  |-  ( { y  |  E. x  e.  A  y  =  B }  C_  C  <->  A. x  e.  A  A. z
( z  =  B  ->  z  e.  C
) )
11 nfv 1437 . . . . 5  |-  F/ z  B  e.  C
12 eleq1 2116 . . . . 5  |-  ( z  =  B  ->  (
z  e.  C  <->  B  e.  C ) )
1311, 12ceqsalg 2599 . . . 4  |-  ( B  e.  D  ->  ( A. z ( z  =  B  ->  z  e.  C )  <->  B  e.  C ) )
1413ralimi 2401 . . 3  |-  ( A. x  e.  A  B  e.  D  ->  A. x  e.  A  ( A. z ( z  =  B  ->  z  e.  C )  <->  B  e.  C ) )
15 ralbi 2462 . . 3  |-  ( A. x  e.  A  ( A. z ( z  =  B  ->  z  e.  C )  <->  B  e.  C )  ->  ( A. x  e.  A  A. z ( z  =  B  ->  z  e.  C )  <->  A. x  e.  A  B  e.  C ) )
1614, 15syl 14 . 2  |-  ( A. x  e.  A  B  e.  D  ->  ( A. x  e.  A  A. z ( z  =  B  ->  z  e.  C )  <->  A. x  e.  A  B  e.  C ) )
1710, 16syl5rbb 186 1  |-  ( A. x  e.  A  B  e.  D  ->  ( A. x  e.  A  B  e.  C  <->  { y  |  E. x  e.  A  y  =  B }  C_  C
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    <-> wb 102   A.wal 1257    = wceq 1259    e. wcel 1409   {cab 2042   A.wral 2323   E.wrex 2324    C_ wss 2945
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 103  ax-ia2 104  ax-ia3 105  ax-io 640  ax-5 1352  ax-7 1353  ax-gen 1354  ax-ie1 1398  ax-ie2 1399  ax-8 1411  ax-10 1412  ax-11 1413  ax-i12 1414  ax-bndl 1415  ax-4 1416  ax-17 1435  ax-i9 1439  ax-ial 1443  ax-i5r 1444  ax-ext 2038
This theorem depends on definitions:  df-bi 114  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-ral 2328  df-rex 2329  df-v 2576  df-in 2952  df-ss 2959
This theorem is referenced by: (None)
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