MPE Home Metamath Proof Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  MPE Home  >  Th. List  >  tppreqb Structured version   Visualization version   Unicode version

Theorem tppreqb 4336
Description: An unordered triple is an unordered pair if and only if one of its elements is a proper class or is identical with one of the another elements. (Contributed by Alexander van der Vekens, 15-Jan-2018.)
Assertion
Ref Expression
tppreqb  |-  ( -.  ( C  e.  _V  /\  C  =/=  A  /\  C  =/=  B )  <->  { A ,  B ,  C }  =  { A ,  B } )

Proof of Theorem tppreqb
StepHypRef Expression
1 3ianor 1055 . . . 4  |-  ( -.  ( C  e.  _V  /\  C  =/=  A  /\  C  =/=  B )  <->  ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
) )
2 df-3or 1038 . . . 4  |-  ( ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
)  <->  ( ( -.  C  e.  _V  \/  -.  C  =/=  A
)  \/  -.  C  =/=  B ) )
31, 2bitri 264 . . 3  |-  ( -.  ( C  e.  _V  /\  C  =/=  A  /\  C  =/=  B )  <->  ( ( -.  C  e.  _V  \/  -.  C  =/=  A
)  \/  -.  C  =/=  B ) )
4 orass 546 . . . . 5  |-  ( ( ( ( -.  C  e.  _V  \/  -.  C  =/=  A )  \/  -.  C  =/=  B )  \/ 
-.  C  e.  _V ) 
<->  ( ( -.  C  e.  _V  \/  -.  C  =/=  A )  \/  ( -.  C  =/=  B  \/  -.  C  e.  _V ) ) )
5 ianor 509 . . . . . . . 8  |-  ( -.  ( C  e.  _V  /\  C  =/=  A )  <-> 
( -.  C  e. 
_V  \/  -.  C  =/=  A ) )
6 tpprceq3 4335 . . . . . . . 8  |-  ( -.  ( C  e.  _V  /\  C  =/=  A )  ->  { B ,  A ,  C }  =  { B ,  A } )
75, 6sylbir 225 . . . . . . 7  |-  ( ( -.  C  e.  _V  \/  -.  C  =/=  A
)  ->  { B ,  A ,  C }  =  { B ,  A } )
8 tpcoma 4285 . . . . . . 7  |-  { B ,  A ,  C }  =  { A ,  B ,  C }
9 prcom 4267 . . . . . . 7  |-  { B ,  A }  =  { A ,  B }
107, 8, 93eqtr3g 2679 . . . . . 6  |-  ( ( -.  C  e.  _V  \/  -.  C  =/=  A
)  ->  { A ,  B ,  C }  =  { A ,  B } )
11 orcom 402 . . . . . . . 8  |-  ( ( -.  C  =/=  B  \/  -.  C  e.  _V ) 
<->  ( -.  C  e. 
_V  \/  -.  C  =/=  B ) )
12 ianor 509 . . . . . . . 8  |-  ( -.  ( C  e.  _V  /\  C  =/=  B )  <-> 
( -.  C  e. 
_V  \/  -.  C  =/=  B ) )
1311, 12bitr4i 267 . . . . . . 7  |-  ( ( -.  C  =/=  B  \/  -.  C  e.  _V ) 
<->  -.  ( C  e. 
_V  /\  C  =/=  B ) )
14 tpprceq3 4335 . . . . . . 7  |-  ( -.  ( C  e.  _V  /\  C  =/=  B )  ->  { A ,  B ,  C }  =  { A ,  B } )
1513, 14sylbi 207 . . . . . 6  |-  ( ( -.  C  =/=  B  \/  -.  C  e.  _V )  ->  { A ,  B ,  C }  =  { A ,  B } )
1610, 15jaoi 394 . . . . 5  |-  ( ( ( -.  C  e. 
_V  \/  -.  C  =/=  A )  \/  ( -.  C  =/=  B  \/  -.  C  e.  _V ) )  ->  { A ,  B ,  C }  =  { A ,  B } )
174, 16sylbi 207 . . . 4  |-  ( ( ( ( -.  C  e.  _V  \/  -.  C  =/=  A )  \/  -.  C  =/=  B )  \/ 
-.  C  e.  _V )  ->  { A ,  B ,  C }  =  { A ,  B } )
1817orcs 409 . . 3  |-  ( ( ( -.  C  e. 
_V  \/  -.  C  =/=  A )  \/  -.  C  =/=  B )  ->  { A ,  B ,  C }  =  { A ,  B }
)
193, 18sylbi 207 . 2  |-  ( -.  ( C  e.  _V  /\  C  =/=  A  /\  C  =/=  B )  ->  { A ,  B ,  C }  =  { A ,  B }
)
20 df-tp 4182 . . . 4  |-  { A ,  B ,  C }  =  ( { A ,  B }  u.  { C } )
2120eqeq1i 2627 . . 3  |-  ( { A ,  B ,  C }  =  { A ,  B }  <->  ( { A ,  B }  u.  { C } )  =  { A ,  B }
)
22 ssequn2 3786 . . . 4  |-  ( { C }  C_  { A ,  B }  <->  ( { A ,  B }  u.  { C } )  =  { A ,  B } )
23 snssg 4327 . . . . . . 7  |-  ( C  e.  _V  ->  ( C  e.  { A ,  B }  <->  { C }  C_  { A ,  B } ) )
24 elpri 4197 . . . . . . . 8  |-  ( C  e.  { A ,  B }  ->  ( C  =  A  \/  C  =  B ) )
25 nne 2798 . . . . . . . . . 10  |-  ( -.  C  =/=  A  <->  C  =  A )
26 3mix2 1231 . . . . . . . . . 10  |-  ( -.  C  =/=  A  -> 
( -.  C  e. 
_V  \/  -.  C  =/=  A  \/  -.  C  =/=  B ) )
2725, 26sylbir 225 . . . . . . . . 9  |-  ( C  =  A  ->  ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
) )
28 nne 2798 . . . . . . . . . 10  |-  ( -.  C  =/=  B  <->  C  =  B )
29 3mix3 1232 . . . . . . . . . 10  |-  ( -.  C  =/=  B  -> 
( -.  C  e. 
_V  \/  -.  C  =/=  A  \/  -.  C  =/=  B ) )
3028, 29sylbir 225 . . . . . . . . 9  |-  ( C  =  B  ->  ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
) )
3127, 30jaoi 394 . . . . . . . 8  |-  ( ( C  =  A  \/  C  =  B )  ->  ( -.  C  e. 
_V  \/  -.  C  =/=  A  \/  -.  C  =/=  B ) )
3224, 31syl 17 . . . . . . 7  |-  ( C  e.  { A ,  B }  ->  ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
) )
3323, 32syl6bir 244 . . . . . 6  |-  ( C  e.  _V  ->  ( { C }  C_  { A ,  B }  ->  ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
) ) )
34 3mix1 1230 . . . . . . 7  |-  ( -.  C  e.  _V  ->  ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
) )
3534a1d 25 . . . . . 6  |-  ( -.  C  e.  _V  ->  ( { C }  C_  { A ,  B }  ->  ( -.  C  e. 
_V  \/  -.  C  =/=  A  \/  -.  C  =/=  B ) ) )
3633, 35pm2.61i 176 . . . . 5  |-  ( { C }  C_  { A ,  B }  ->  ( -.  C  e.  _V  \/  -.  C  =/=  A  \/  -.  C  =/=  B
) )
3736, 1sylibr 224 . . . 4  |-  ( { C }  C_  { A ,  B }  ->  -.  ( C  e.  _V  /\  C  =/=  A  /\  C  =/=  B ) )
3822, 37sylbir 225 . . 3  |-  ( ( { A ,  B }  u.  { C } )  =  { A ,  B }  ->  -.  ( C  e. 
_V  /\  C  =/=  A  /\  C  =/=  B
) )
3921, 38sylbi 207 . 2  |-  ( { A ,  B ,  C }  =  { A ,  B }  ->  -.  ( C  e. 
_V  /\  C  =/=  A  /\  C  =/=  B
) )
4019, 39impbii 199 1  |-  ( -.  ( C  e.  _V  /\  C  =/=  A  /\  C  =/=  B )  <->  { A ,  B ,  C }  =  { A ,  B } )
Colors of variables: wff setvar class
Syntax hints:   -. wn 3    -> wi 4    <-> wb 196    \/ wo 383    /\ wa 384    \/ w3o 1036    /\ w3a 1037    = wceq 1483    e. wcel 1990    =/= wne 2794   _Vcvv 3200    u. cun 3572    C_ wss 3574   {csn 4177   {cpr 4179   {ctp 4181
This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1722  ax-4 1737  ax-5 1839  ax-6 1888  ax-7 1935  ax-9 1999  ax-10 2019  ax-11 2034  ax-12 2047  ax-13 2246  ax-ext 2602
This theorem depends on definitions:  df-bi 197  df-or 385  df-an 386  df-3or 1038  df-3an 1039  df-tru 1486  df-ex 1705  df-nf 1710  df-sb 1881  df-clab 2609  df-cleq 2615  df-clel 2618  df-nfc 2753  df-ne 2795  df-v 3202  df-dif 3577  df-un 3579  df-in 3581  df-ss 3588  df-nul 3916  df-sn 4178  df-pr 4180  df-tp 4182
This theorem is referenced by: (None)
  Copyright terms: Public domain W3C validator