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Theorem iunab 3948
Description: The indexed union of a class abstraction. (Contributed by NM, 27-Dec-2004.)
Assertion
Ref Expression
iunab  |-  U_ x  e.  A  { y  |  ph }  =  {
y  |  E. x  e.  A  ph }
Distinct variable groups:    y, A    x, y
Allowed substitution hints:    ph( x, y)    A( x)

Proof of Theorem iunab
StepHypRef Expression
1 nfcv 2419 . . . 4  |-  F/_ y A
2 nfab1 2421 . . . 4  |-  F/_ y { y  |  ph }
31, 2nfiun 3931 . . 3  |-  F/_ y U_ x  e.  A  { y  |  ph }
4 nfab1 2421 . . 3  |-  F/_ y { y  |  E. x  e.  A  ph }
53, 4cleqf 2443 . 2  |-  ( U_ x  e.  A  {
y  |  ph }  =  { y  |  E. x  e.  A  ph }  <->  A. y ( y  e. 
U_ x  e.  A  { y  |  ph } 
<->  y  e.  { y  |  E. x  e.  A  ph } ) )
6 abid 2271 . . . 4  |-  ( y  e.  { y  | 
ph }  <->  ph )
76rexbii 2568 . . 3  |-  ( E. x  e.  A  y  e.  { y  | 
ph }  <->  E. x  e.  A  ph )
8 eliun 3909 . . 3  |-  ( y  e.  U_ x  e.  A  { y  | 
ph }  <->  E. x  e.  A  y  e.  { y  |  ph }
)
9 abid 2271 . . 3  |-  ( y  e.  { y  |  E. x  e.  A  ph }  <->  E. x  e.  A  ph )
107, 8, 93bitr4i 268 . 2  |-  ( y  e.  U_ x  e.  A  { y  | 
ph }  <->  y  e.  { y  |  E. x  e.  A  ph } )
115, 10mpgbir 1537 1  |-  U_ x  e.  A  { y  |  ph }  =  {
y  |  E. x  e.  A  ph }
Colors of variables: wff set class
Syntax hints:    <-> wb 176    = wceq 1623    e. wcel 1684   {cab 2269   E.wrex 2544   U_ciun 3905
This theorem is referenced by:  iunrab  3949  iunid  3957  dfimafn2  5572  sallnei  25529  iscola2  26092  dfaimafn2  28028
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1533  ax-5 1544  ax-17 1603  ax-9 1635  ax-8 1643  ax-6 1703  ax-7 1708  ax-11 1715  ax-12 1866  ax-ext 2264
This theorem depends on definitions:  df-bi 177  df-or 359  df-an 360  df-tru 1310  df-ex 1529  df-nf 1532  df-sb 1630  df-clab 2270  df-cleq 2276  df-clel 2279  df-nfc 2408  df-ral 2548  df-rex 2549  df-v 2790  df-iun 3907
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