ILE Home Intuitionistic Logic Explorer < Previous   Next >
Nearby theorems
Mirrors  >  Home  >  ILE Home  >  Th. List  >  opth1 Unicode version

Theorem opth1 3999
Description: Equality of the first members of equal ordered pairs. (Contributed by NM, 28-May-2008.) (Revised by Mario Carneiro, 26-Apr-2015.)
Hypotheses
Ref Expression
opth1.1  |-  A  e. 
_V
opth1.2  |-  B  e. 
_V
Assertion
Ref Expression
opth1  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  A  =  C )

Proof of Theorem opth1
StepHypRef Expression
1 opth1.1 . . . 4  |-  A  e. 
_V
21sneqr 3560 . . 3  |-  ( { A }  =  { C }  ->  A  =  C )
32a1i 9 . 2  |-  ( <. A ,  B >.  = 
<. C ,  D >.  -> 
( { A }  =  { C }  ->  A  =  C ) )
4 opth1.2 . . . . . . . . 9  |-  B  e. 
_V
51, 4opi1 3995 . . . . . . . 8  |-  { A }  e.  <. A ,  B >.
6 id 19 . . . . . . . 8  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  <. A ,  B >.  = 
<. C ,  D >. )
75, 6syl5eleq 2168 . . . . . . 7  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  { A }  e.  <. C ,  D >. )
8 oprcl 3602 . . . . . . 7  |-  ( { A }  e.  <. C ,  D >.  ->  ( C  e.  _V  /\  D  e.  _V ) )
97, 8syl 14 . . . . . 6  |-  ( <. A ,  B >.  = 
<. C ,  D >.  -> 
( C  e.  _V  /\  D  e.  _V )
)
109simpld 110 . . . . 5  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  C  e.  _V )
11 prid1g 3504 . . . . 5  |-  ( C  e.  _V  ->  C  e.  { C ,  D } )
1210, 11syl 14 . . . 4  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  C  e.  { C ,  D } )
13 eleq2 2143 . . . 4  |-  ( { A }  =  { C ,  D }  ->  ( C  e.  { A }  <->  C  e.  { C ,  D } ) )
1412, 13syl5ibrcom 155 . . 3  |-  ( <. A ,  B >.  = 
<. C ,  D >.  -> 
( { A }  =  { C ,  D }  ->  C  e.  { A } ) )
15 elsni 3424 . . . 4  |-  ( C  e.  { A }  ->  C  =  A )
1615eqcomd 2087 . . 3  |-  ( C  e.  { A }  ->  A  =  C )
1714, 16syl6 33 . 2  |-  ( <. A ,  B >.  = 
<. C ,  D >.  -> 
( { A }  =  { C ,  D }  ->  A  =  C ) )
18 dfopg 3576 . . . . 5  |-  ( ( C  e.  _V  /\  D  e.  _V )  -> 
<. C ,  D >.  =  { { C } ,  { C ,  D } } )
197, 8, 183syl 17 . . . 4  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  <. C ,  D >.  =  { { C } ,  { C ,  D } } )
207, 19eleqtrd 2158 . . 3  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  { A }  e.  { { C } ,  { C ,  D } } )
21 elpri 3429 . . 3  |-  ( { A }  e.  { { C } ,  { C ,  D } }  ->  ( { A }  =  { C }  \/  { A }  =  { C ,  D } ) )
2220, 21syl 14 . 2  |-  ( <. A ,  B >.  = 
<. C ,  D >.  -> 
( { A }  =  { C }  \/  { A }  =  { C ,  D }
) )
233, 17, 22mpjaod 671 1  |-  ( <. A ,  B >.  = 
<. C ,  D >.  ->  A  =  C )
Colors of variables: wff set class
Syntax hints:    -> wi 4    /\ wa 102    \/ wo 662    = wceq 1285    e. wcel 1434   _Vcvv 2602   {csn 3406   {cpr 3407   <.cop 3409
This theorem was proved from axioms:  ax-1 5  ax-2 6  ax-mp 7  ax-ia1 104  ax-ia2 105  ax-ia3 106  ax-io 663  ax-5 1377  ax-7 1378  ax-gen 1379  ax-ie1 1423  ax-ie2 1424  ax-8 1436  ax-10 1437  ax-11 1438  ax-i12 1439  ax-bndl 1440  ax-4 1441  ax-14 1446  ax-17 1460  ax-i9 1464  ax-ial 1468  ax-i5r 1469  ax-ext 2064  ax-sep 3904  ax-pow 3956
This theorem depends on definitions:  df-bi 115  df-3an 922  df-tru 1288  df-nf 1391  df-sb 1687  df-clab 2069  df-cleq 2075  df-clel 2078  df-nfc 2209  df-v 2604  df-un 2978  df-in 2980  df-ss 2987  df-pw 3392  df-sn 3412  df-pr 3413  df-op 3415
This theorem is referenced by:  opth  4000  dmsnopg  4822  funcnvsn  4975  oprabid  5568
  Copyright terms: Public domain W3C validator