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Theorem pm13.196a 27625
Description: Theorem *13.196 in [WhiteheadRussell] p. 179. The only difference is the position of the substituted variable. (Contributed by Andrew Salmon, 3-Jun-2011.)
Assertion
Ref Expression
pm13.196a  |-  ( -. 
ph 
<-> 
A. y ( [ y  /  x ] ph  ->  y  =/=  x
) )
Distinct variable groups:    x, y    ph, y
Allowed substitution hint:    ph( x)

Proof of Theorem pm13.196a
StepHypRef Expression
1 sbelx 2065 . 2  |-  ( -. 
ph 
<->  E. y ( y  =  x  /\  [
y  /  x ]  -.  ph ) )
2 sb56 2039 . 2  |-  ( E. y ( y  =  x  /\  [ y  /  x ]  -.  ph )  <->  A. y ( y  =  x  ->  [ y  /  x ]  -.  ph ) )
3 sbn 2004 . . . . 5  |-  ( [ y  /  x ]  -.  ph  <->  -.  [ y  /  x ] ph )
43imbi2i 303 . . . 4  |-  ( ( y  =  x  ->  [ y  /  x ]  -.  ph )  <->  ( y  =  x  ->  -.  [
y  /  x ] ph ) )
5 con2b 324 . . . 4  |-  ( ( y  =  x  ->  -.  [ y  /  x ] ph )  <->  ( [
y  /  x ] ph  ->  -.  y  =  x ) )
6 df-ne 2450 . . . . . 6  |-  ( y  =/=  x  <->  -.  y  =  x )
76bicomi 193 . . . . 5  |-  ( -.  y  =  x  <->  y  =/=  x )
87imbi2i 303 . . . 4  |-  ( ( [ y  /  x ] ph  ->  -.  y  =  x )  <->  ( [
y  /  x ] ph  ->  y  =/=  x
) )
94, 5, 83bitri 262 . . 3  |-  ( ( y  =  x  ->  [ y  /  x ]  -.  ph )  <->  ( [
y  /  x ] ph  ->  y  =/=  x
) )
109albii 1555 . 2  |-  ( A. y ( y  =  x  ->  [ y  /  x ]  -.  ph ) 
<-> 
A. y ( [ y  /  x ] ph  ->  y  =/=  x
) )
111, 2, 103bitri 262 1  |-  ( -. 
ph 
<-> 
A. y ( [ y  /  x ] ph  ->  y  =/=  x
) )
Colors of variables: wff set class
Syntax hints:   -. wn 3    -> wi 4    <-> wb 176    /\ wa 358   A.wal 1529   E.wex 1530    = wceq 1625   [wsb 1631    =/= wne 2448
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-3 7  ax-mp 8  ax-gen 1535  ax-5 1546  ax-17 1605  ax-9 1637  ax-8 1645  ax-6 1705  ax-7 1710  ax-11 1717  ax-12 1868
This theorem depends on definitions:  df-bi 177  df-an 360  df-tru 1310  df-ex 1531  df-nf 1534  df-sb 1632  df-ne 2450
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