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Theorem rextpg 3452
Description: Convert a quantification over a triple to a disjunction. (Contributed by Mario Carneiro, 23-Apr-2015.)
Hypotheses
Ref Expression
ralprg.1  |-  ( x  =  A  ->  ( ph 
<->  ps ) )
ralprg.2  |-  ( x  =  B  ->  ( ph 
<->  ch ) )
raltpg.3  |-  ( x  =  C  ->  ( ph 
<->  th ) )
Assertion
Ref Expression
rextpg  |-  ( ( A  e.  V  /\  B  e.  W  /\  C  e.  X )  ->  ( E. x  e. 
{ A ,  B ,  C } ph  <->  ( ps  \/  ch  \/  th )
) )
Distinct variable groups:    x, A    x, B    x, C    ps, x    ch, x    th, x
Allowed substitution hints:    ph( x)    V( x)    W( x)    X( x)

Proof of Theorem rextpg
StepHypRef Expression
1 ralprg.1 . . . . . 6  |-  ( x  =  A  ->  ( ph 
<->  ps ) )
2 ralprg.2 . . . . . 6  |-  ( x  =  B  ->  ( ph 
<->  ch ) )
31, 2rexprg 3450 . . . . 5  |-  ( ( A  e.  V  /\  B  e.  W )  ->  ( E. x  e. 
{ A ,  B } ph  <->  ( ps  \/  ch ) ) )
43orbi1d 715 . . . 4  |-  ( ( A  e.  V  /\  B  e.  W )  ->  ( ( E. x  e.  { A ,  B } ph  \/  E. x  e.  { C } ph ) 
<->  ( ( ps  \/  ch )  \/  E. x  e.  { C } ph ) ) )
5 raltpg.3 . . . . . 6  |-  ( x  =  C  ->  ( ph 
<->  th ) )
65rexsng 3440 . . . . 5  |-  ( C  e.  X  ->  ( E. x  e.  { C } ph  <->  th ) )
76orbi2d 714 . . . 4  |-  ( C  e.  X  ->  (
( ( ps  \/  ch )  \/  E. x  e.  { C } ph ) 
<->  ( ( ps  \/  ch )  \/  th )
) )
84, 7sylan9bb 443 . . 3  |-  ( ( ( A  e.  V  /\  B  e.  W
)  /\  C  e.  X )  ->  (
( E. x  e. 
{ A ,  B } ph  \/  E. x  e.  { C } ph ) 
<->  ( ( ps  \/  ch )  \/  th )
) )
983impa 1110 . 2  |-  ( ( A  e.  V  /\  B  e.  W  /\  C  e.  X )  ->  ( ( E. x  e.  { A ,  B } ph  \/  E. x  e.  { C } ph ) 
<->  ( ( ps  \/  ch )  \/  th )
) )
10 df-tp 3411 . . . 4  |-  { A ,  B ,  C }  =  ( { A ,  B }  u.  { C } )
1110rexeqi 2527 . . 3  |-  ( E. x  e.  { A ,  B ,  C } ph 
<->  E. x  e.  ( { A ,  B }  u.  { C } ) ph )
12 rexun 3151 . . 3  |-  ( E. x  e.  ( { A ,  B }  u.  { C } )
ph 
<->  ( E. x  e. 
{ A ,  B } ph  \/  E. x  e.  { C } ph ) )
1311, 12bitri 177 . 2  |-  ( E. x  e.  { A ,  B ,  C } ph 
<->  ( E. x  e. 
{ A ,  B } ph  \/  E. x  e.  { C } ph ) )
14 df-3or 897 . 2  |-  ( ( ps  \/  ch  \/  th )  <->  ( ( ps  \/  ch )  \/ 
th ) )
159, 13, 143bitr4g 216 1  |-  ( ( A  e.  V  /\  B  e.  W  /\  C  e.  X )  ->  ( E. x  e. 
{ A ,  B ,  C } ph  <->  ( ps  \/  ch  \/  th )
) )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 101    <-> wb 102    \/ wo 639    \/ w3o 895    /\ w3a 896    = wceq 1259    e. wcel 1409   E.wrex 2324    u. cun 2943   {csn 3403   {cpr 3404   {ctp 3405
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-3or 897  df-3an 898  df-tru 1262  df-nf 1366  df-sb 1662  df-clab 2043  df-cleq 2049  df-clel 2052  df-nfc 2183  df-rex 2329  df-v 2576  df-sbc 2788  df-un 2950  df-sn 3409  df-pr 3410  df-tp 3411
This theorem is referenced by:  rextp  3456
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