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Theorem nfabd2 2450
Description: Bound-variable hypothesis builder for a class abstraction. (Contributed by Mario Carneiro, 8-Oct-2016.)
Hypotheses
Ref Expression
nfabd2.1  |-  F/ y
ph
nfabd2.2  |-  ( (
ph  /\  -.  A. x  x  =  y )  ->  F/ x ps )
Assertion
Ref Expression
nfabd2  |-  ( ph  -> 
F/_ x { y  |  ps } )

Proof of Theorem nfabd2
Dummy variable  z is distinct from all other variables.
StepHypRef Expression
1 nfv 1609 . . . 4  |-  F/ z ( ph  /\  -.  A. x  x  =  y )
2 df-clab 2283 . . . . 5  |-  ( z  e.  { y  |  ps }  <->  [ z  /  y ] ps )
3 nfabd2.1 . . . . . . 7  |-  F/ y
ph
4 nfnae 1909 . . . . . . 7  |-  F/ y  -.  A. x  x  =  y
53, 4nfan 1783 . . . . . 6  |-  F/ y ( ph  /\  -.  A. x  x  =  y )
6 nfabd2.2 . . . . . 6  |-  ( (
ph  /\  -.  A. x  x  =  y )  ->  F/ x ps )
75, 6nfsbd 2063 . . . . 5  |-  ( (
ph  /\  -.  A. x  x  =  y )  ->  F/ x [ z  /  y ] ps )
82, 7nfxfrd 1561 . . . 4  |-  ( (
ph  /\  -.  A. x  x  =  y )  ->  F/ x  z  e. 
{ y  |  ps } )
91, 8nfcd 2427 . . 3  |-  ( (
ph  /\  -.  A. x  x  =  y )  -> 
F/_ x { y  |  ps } )
109ex 423 . 2  |-  ( ph  ->  ( -.  A. x  x  =  y  ->  F/_ x { y  |  ps } ) )
11 nfab1 2434 . . 3  |-  F/_ y { y  |  ps }
12 eqidd 2297 . . . 4  |-  ( A. x  x  =  y  ->  { y  |  ps }  =  { y  |  ps } )
1312drnfc1 2448 . . 3  |-  ( A. x  x  =  y  ->  ( F/_ x {
y  |  ps }  <->  F/_ y { y  |  ps } ) )
1411, 13mpbiri 224 . 2  |-  ( A. x  x  =  y  -> 
F/_ x { y  |  ps } )
1510, 14pm2.61d2 152 1  |-  ( ph  -> 
F/_ x { y  |  ps } )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    /\ wa 358   A.wal 1530   F/wnf 1534    = wceq 1632   [wsb 1638    e. wcel 1696   {cab 2282   F/_wnfc 2419
This theorem is referenced by:  nfabd  2451  nfrab  2734  nfriotad  6329  nfixp  6851
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1536  ax-5 1547  ax-17 1606  ax-9 1644  ax-8 1661  ax-6 1715  ax-7 1720  ax-11 1727  ax-12 1878  ax-ext 2277
This theorem depends on definitions:  df-bi 177  df-an 360  df-tru 1310  df-ex 1532  df-nf 1535  df-sb 1639  df-clab 2283  df-cleq 2289  df-clel 2292  df-nfc 2421
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