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Theorem euind 2871
Description: Existential uniqueness via an indirect equality. (Contributed by NM, 11-Oct-2010.)
Hypotheses
Ref Expression
euind.1  |-  B  e. 
_V
euind.2  |-  ( x  =  y  ->  ( ph 
<->  ps ) )
euind.3  |-  ( x  =  y  ->  A  =  B )
Assertion
Ref Expression
euind  |-  ( ( A. x A. y
( ( ph  /\  ps )  ->  A  =  B )  /\  E. x ph )  ->  E! z A. x ( ph  ->  z  =  A ) )
Distinct variable groups:    y, z, ph    x, z, ps    y, A, z    x, B, z    x, y
Allowed substitution hints:    ph( x)    ps( y)    A( x)    B( y)

Proof of Theorem euind
Dummy variable  w is distinct from all other variables.
StepHypRef Expression
1 euind.2 . . . . . 6  |-  ( x  =  y  ->  ( ph 
<->  ps ) )
21cbvexv 1890 . . . . 5  |-  ( E. x ph  <->  E. y ps )
3 euind.1 . . . . . . . . 9  |-  B  e. 
_V
43isseti 2694 . . . . . . . 8  |-  E. z 
z  =  B
54biantrur 301 . . . . . . 7  |-  ( ps  <->  ( E. z  z  =  B  /\  ps )
)
65exbii 1584 . . . . . 6  |-  ( E. y ps  <->  E. y
( E. z  z  =  B  /\  ps ) )
7 19.41v 1874 . . . . . . 7  |-  ( E. z ( z  =  B  /\  ps )  <->  ( E. z  z  =  B  /\  ps )
)
87exbii 1584 . . . . . 6  |-  ( E. y E. z ( z  =  B  /\  ps )  <->  E. y ( E. z  z  =  B  /\  ps ) )
9 excom 1642 . . . . . 6  |-  ( E. y E. z ( z  =  B  /\  ps )  <->  E. z E. y
( z  =  B  /\  ps ) )
106, 8, 93bitr2i 207 . . . . 5  |-  ( E. y ps  <->  E. z E. y ( z  =  B  /\  ps )
)
112, 10bitri 183 . . . 4  |-  ( E. x ph  <->  E. z E. y ( z  =  B  /\  ps )
)
12 eqeq2 2149 . . . . . . . . 9  |-  ( A  =  B  ->  (
z  =  A  <->  z  =  B ) )
1312imim2i 12 . . . . . . . 8  |-  ( ( ( ph  /\  ps )  ->  A  =  B )  ->  ( ( ph  /\  ps )  -> 
( z  =  A  <-> 
z  =  B ) ) )
14 bi2 129 . . . . . . . . . 10  |-  ( ( z  =  A  <->  z  =  B )  ->  (
z  =  B  -> 
z  =  A ) )
1514imim2i 12 . . . . . . . . 9  |-  ( ( ( ph  /\  ps )  ->  ( z  =  A  <->  z  =  B ) )  ->  (
( ph  /\  ps )  ->  ( z  =  B  ->  z  =  A ) ) )
16 an31 553 . . . . . . . . . . 11  |-  ( ( ( ph  /\  ps )  /\  z  =  B )  <->  ( ( z  =  B  /\  ps )  /\  ph ) )
1716imbi1i 237 . . . . . . . . . 10  |-  ( ( ( ( ph  /\  ps )  /\  z  =  B )  ->  z  =  A )  <->  ( (
( z  =  B  /\  ps )  /\  ph )  ->  z  =  A ) )
18 impexp 261 . . . . . . . . . 10  |-  ( ( ( ( ph  /\  ps )  /\  z  =  B )  ->  z  =  A )  <->  ( ( ph  /\  ps )  -> 
( z  =  B  ->  z  =  A ) ) )
19 impexp 261 . . . . . . . . . 10  |-  ( ( ( ( z  =  B  /\  ps )  /\  ph )  ->  z  =  A )  <->  ( (
z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) ) )
2017, 18, 193bitr3i 209 . . . . . . . . 9  |-  ( ( ( ph  /\  ps )  ->  ( z  =  B  ->  z  =  A ) )  <->  ( (
z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) ) )
2115, 20sylib 121 . . . . . . . 8  |-  ( ( ( ph  /\  ps )  ->  ( z  =  A  <->  z  =  B ) )  ->  (
( z  =  B  /\  ps )  -> 
( ph  ->  z  =  A ) ) )
2213, 21syl 14 . . . . . . 7  |-  ( ( ( ph  /\  ps )  ->  A  =  B )  ->  ( (
z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) ) )
23222alimi 1432 . . . . . 6  |-  ( A. x A. y ( (
ph  /\  ps )  ->  A  =  B )  ->  A. x A. y
( ( z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) ) )
24 19.23v 1855 . . . . . . . 8  |-  ( A. y ( ( z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) )  <-> 
( E. y ( z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) ) )
2524albii 1446 . . . . . . 7  |-  ( A. x A. y ( ( z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) )  <->  A. x ( E. y ( z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) ) )
26 19.21v 1845 . . . . . . 7  |-  ( A. x ( E. y
( z  =  B  /\  ps )  -> 
( ph  ->  z  =  A ) )  <->  ( E. y ( z  =  B  /\  ps )  ->  A. x ( ph  ->  z  =  A ) ) )
2725, 26bitri 183 . . . . . 6  |-  ( A. x A. y ( ( z  =  B  /\  ps )  ->  ( ph  ->  z  =  A ) )  <->  ( E. y
( z  =  B  /\  ps )  ->  A. x ( ph  ->  z  =  A ) ) )
2823, 27sylib 121 . . . . 5  |-  ( A. x A. y ( (
ph  /\  ps )  ->  A  =  B )  ->  ( E. y
( z  =  B  /\  ps )  ->  A. x ( ph  ->  z  =  A ) ) )
2928eximdv 1852 . . . 4  |-  ( A. x A. y ( (
ph  /\  ps )  ->  A  =  B )  ->  ( E. z E. y ( z  =  B  /\  ps )  ->  E. z A. x
( ph  ->  z  =  A ) ) )
3011, 29syl5bi 151 . . 3  |-  ( A. x A. y ( (
ph  /\  ps )  ->  A  =  B )  ->  ( E. x ph  ->  E. z A. x
( ph  ->  z  =  A ) ) )
3130imp 123 . 2  |-  ( ( A. x A. y
( ( ph  /\  ps )  ->  A  =  B )  /\  E. x ph )  ->  E. z A. x ( ph  ->  z  =  A ) )
32 pm4.24 392 . . . . . . . 8  |-  ( ph  <->  (
ph  /\  ph ) )
3332biimpi 119 . . . . . . 7  |-  ( ph  ->  ( ph  /\  ph ) )
34 anim12 341 . . . . . . 7  |-  ( ( ( ph  ->  z  =  A )  /\  ( ph  ->  w  =  A ) )  ->  (
( ph  /\  ph )  ->  ( z  =  A  /\  w  =  A ) ) )
35 eqtr3 2159 . . . . . . 7  |-  ( ( z  =  A  /\  w  =  A )  ->  z  =  w )
3633, 34, 35syl56 34 . . . . . 6  |-  ( ( ( ph  ->  z  =  A )  /\  ( ph  ->  w  =  A ) )  ->  ( ph  ->  z  =  w ) )
3736alanimi 1435 . . . . 5  |-  ( ( A. x ( ph  ->  z  =  A )  /\  A. x (
ph  ->  w  =  A ) )  ->  A. x
( ph  ->  z  =  w ) )
38 19.23v 1855 . . . . . . 7  |-  ( A. x ( ph  ->  z  =  w )  <->  ( E. x ph  ->  z  =  w ) )
3938biimpi 119 . . . . . 6  |-  ( A. x ( ph  ->  z  =  w )  -> 
( E. x ph  ->  z  =  w ) )
4039com12 30 . . . . 5  |-  ( E. x ph  ->  ( A. x ( ph  ->  z  =  w )  -> 
z  =  w ) )
4137, 40syl5 32 . . . 4  |-  ( E. x ph  ->  (
( A. x (
ph  ->  z  =  A )  /\  A. x
( ph  ->  w  =  A ) )  -> 
z  =  w ) )
4241alrimivv 1847 . . 3  |-  ( E. x ph  ->  A. z A. w ( ( A. x ( ph  ->  z  =  A )  /\  A. x ( ph  ->  w  =  A ) )  ->  z  =  w ) )
4342adantl 275 . 2  |-  ( ( A. x A. y
( ( ph  /\  ps )  ->  A  =  B )  /\  E. x ph )  ->  A. z A. w ( ( A. x ( ph  ->  z  =  A )  /\  A. x ( ph  ->  w  =  A ) )  ->  z  =  w ) )
44 eqeq1 2146 . . . . 5  |-  ( z  =  w  ->  (
z  =  A  <->  w  =  A ) )
4544imbi2d 229 . . . 4  |-  ( z  =  w  ->  (
( ph  ->  z  =  A )  <->  ( ph  ->  w  =  A ) ) )
4645albidv 1796 . . 3  |-  ( z  =  w  ->  ( A. x ( ph  ->  z  =  A )  <->  A. x
( ph  ->  w  =  A ) ) )
4746eu4 2061 . 2  |-  ( E! z A. x (
ph  ->  z  =  A )  <->  ( E. z A. x ( ph  ->  z  =  A )  /\  A. z A. w ( ( A. x (
ph  ->  z  =  A )  /\  A. x
( ph  ->  w  =  A ) )  -> 
z  =  w ) ) )
4831, 43, 47sylanbrc 413 1  |-  ( ( A. x A. y
( ( ph  /\  ps )  ->  A  =  B )  /\  E. x ph )  ->  E! z A. x ( ph  ->  z  =  A ) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 103    <-> wb 104   A.wal 1329    = wceq 1331   E.wex 1468    e. wcel 1480   E!weu 1999   _Vcvv 2686
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 698  ax-5 1423  ax-7 1424  ax-gen 1425  ax-ie1 1469  ax-ie2 1470  ax-8 1482  ax-10 1483  ax-11 1484  ax-i12 1485  ax-bndl 1486  ax-4 1487  ax-17 1506  ax-i9 1510  ax-ial 1514  ax-i5r 1515  ax-ext 2121
This theorem depends on definitions:  df-bi 116  df-nf 1437  df-sb 1736  df-eu 2002  df-mo 2003  df-clab 2126  df-cleq 2132  df-clel 2135  df-v 2688
This theorem is referenced by: (None)
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