| Step | Hyp | Ref | Expression | 
						
							| 1 |  | colinrel |  |-  Rel Colinear | 
						
							| 2 | 1 | brrelex1i |  |-  ( P Colinear <. Q , R >. -> P e. _V ) | 
						
							| 3 | 2 | a1i |  |-  ( ( Q e. V /\ R e. W ) -> ( P Colinear <. Q , R >. -> P e. _V ) ) | 
						
							| 4 |  | elex |  |-  ( P e. ( EE ` n ) -> P e. _V ) | 
						
							| 5 | 4 | 3ad2ant1 |  |-  ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) -> P e. _V ) | 
						
							| 6 | 5 | adantr |  |-  ( ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) -> P e. _V ) | 
						
							| 7 | 6 | rexlimivw |  |-  ( E. n e. NN ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) -> P e. _V ) | 
						
							| 8 | 7 | a1i |  |-  ( ( Q e. V /\ R e. W ) -> ( E. n e. NN ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) -> P e. _V ) ) | 
						
							| 9 |  | df-br |  |-  ( P Colinear <. Q , R >. <-> <. P , <. Q , R >. >. e. Colinear ) | 
						
							| 10 |  | df-colinear |  |-  Colinear = `' { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } | 
						
							| 11 | 10 | eleq2i |  |-  ( <. P , <. Q , R >. >. e. Colinear <-> <. P , <. Q , R >. >. e. `' { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } ) | 
						
							| 12 | 9 11 | bitri |  |-  ( P Colinear <. Q , R >. <-> <. P , <. Q , R >. >. e. `' { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } ) | 
						
							| 13 |  | opex |  |-  <. Q , R >. e. _V | 
						
							| 14 |  | opelcnvg |  |-  ( ( P e. _V /\ <. Q , R >. e. _V ) -> ( <. P , <. Q , R >. >. e. `' { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } <-> <. <. Q , R >. , P >. e. { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } ) ) | 
						
							| 15 | 13 14 | mpan2 |  |-  ( P e. _V -> ( <. P , <. Q , R >. >. e. `' { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } <-> <. <. Q , R >. , P >. e. { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } ) ) | 
						
							| 16 | 15 | 3ad2ant3 |  |-  ( ( Q e. V /\ R e. W /\ P e. _V ) -> ( <. P , <. Q , R >. >. e. `' { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } <-> <. <. Q , R >. , P >. e. { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } ) ) | 
						
							| 17 | 12 16 | bitrid |  |-  ( ( Q e. V /\ R e. W /\ P e. _V ) -> ( P Colinear <. Q , R >. <-> <. <. Q , R >. , P >. e. { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } ) ) | 
						
							| 18 |  | eleq1 |  |-  ( q = Q -> ( q e. ( EE ` n ) <-> Q e. ( EE ` n ) ) ) | 
						
							| 19 | 18 | 3anbi2d |  |-  ( q = Q -> ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) <-> ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ r e. ( EE ` n ) ) ) ) | 
						
							| 20 |  | opeq1 |  |-  ( q = Q -> <. q , r >. = <. Q , r >. ) | 
						
							| 21 | 20 | breq2d |  |-  ( q = Q -> ( p Btwn <. q , r >. <-> p Btwn <. Q , r >. ) ) | 
						
							| 22 |  | breq1 |  |-  ( q = Q -> ( q Btwn <. r , p >. <-> Q Btwn <. r , p >. ) ) | 
						
							| 23 |  | opeq2 |  |-  ( q = Q -> <. p , q >. = <. p , Q >. ) | 
						
							| 24 | 23 | breq2d |  |-  ( q = Q -> ( r Btwn <. p , q >. <-> r Btwn <. p , Q >. ) ) | 
						
							| 25 | 21 22 24 | 3orbi123d |  |-  ( q = Q -> ( ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) <-> ( p Btwn <. Q , r >. \/ Q Btwn <. r , p >. \/ r Btwn <. p , Q >. ) ) ) | 
						
							| 26 | 19 25 | anbi12d |  |-  ( q = Q -> ( ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) <-> ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. Q , r >. \/ Q Btwn <. r , p >. \/ r Btwn <. p , Q >. ) ) ) ) | 
						
							| 27 | 26 | rexbidv |  |-  ( q = Q -> ( E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) <-> E. n e. NN ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. Q , r >. \/ Q Btwn <. r , p >. \/ r Btwn <. p , Q >. ) ) ) ) | 
						
							| 28 |  | eleq1 |  |-  ( r = R -> ( r e. ( EE ` n ) <-> R e. ( EE ` n ) ) ) | 
						
							| 29 | 28 | 3anbi3d |  |-  ( r = R -> ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ r e. ( EE ` n ) ) <-> ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) ) ) | 
						
							| 30 |  | opeq2 |  |-  ( r = R -> <. Q , r >. = <. Q , R >. ) | 
						
							| 31 | 30 | breq2d |  |-  ( r = R -> ( p Btwn <. Q , r >. <-> p Btwn <. Q , R >. ) ) | 
						
							| 32 |  | opeq1 |  |-  ( r = R -> <. r , p >. = <. R , p >. ) | 
						
							| 33 | 32 | breq2d |  |-  ( r = R -> ( Q Btwn <. r , p >. <-> Q Btwn <. R , p >. ) ) | 
						
							| 34 |  | breq1 |  |-  ( r = R -> ( r Btwn <. p , Q >. <-> R Btwn <. p , Q >. ) ) | 
						
							| 35 | 31 33 34 | 3orbi123d |  |-  ( r = R -> ( ( p Btwn <. Q , r >. \/ Q Btwn <. r , p >. \/ r Btwn <. p , Q >. ) <-> ( p Btwn <. Q , R >. \/ Q Btwn <. R , p >. \/ R Btwn <. p , Q >. ) ) ) | 
						
							| 36 | 29 35 | anbi12d |  |-  ( r = R -> ( ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. Q , r >. \/ Q Btwn <. r , p >. \/ r Btwn <. p , Q >. ) ) <-> ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( p Btwn <. Q , R >. \/ Q Btwn <. R , p >. \/ R Btwn <. p , Q >. ) ) ) ) | 
						
							| 37 | 36 | rexbidv |  |-  ( r = R -> ( E. n e. NN ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. Q , r >. \/ Q Btwn <. r , p >. \/ r Btwn <. p , Q >. ) ) <-> E. n e. NN ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( p Btwn <. Q , R >. \/ Q Btwn <. R , p >. \/ R Btwn <. p , Q >. ) ) ) ) | 
						
							| 38 |  | eleq1 |  |-  ( p = P -> ( p e. ( EE ` n ) <-> P e. ( EE ` n ) ) ) | 
						
							| 39 | 38 | 3anbi1d |  |-  ( p = P -> ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) <-> ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) ) ) | 
						
							| 40 |  | breq1 |  |-  ( p = P -> ( p Btwn <. Q , R >. <-> P Btwn <. Q , R >. ) ) | 
						
							| 41 |  | opeq2 |  |-  ( p = P -> <. R , p >. = <. R , P >. ) | 
						
							| 42 | 41 | breq2d |  |-  ( p = P -> ( Q Btwn <. R , p >. <-> Q Btwn <. R , P >. ) ) | 
						
							| 43 |  | opeq1 |  |-  ( p = P -> <. p , Q >. = <. P , Q >. ) | 
						
							| 44 | 43 | breq2d |  |-  ( p = P -> ( R Btwn <. p , Q >. <-> R Btwn <. P , Q >. ) ) | 
						
							| 45 | 40 42 44 | 3orbi123d |  |-  ( p = P -> ( ( p Btwn <. Q , R >. \/ Q Btwn <. R , p >. \/ R Btwn <. p , Q >. ) <-> ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) ) | 
						
							| 46 | 39 45 | anbi12d |  |-  ( p = P -> ( ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( p Btwn <. Q , R >. \/ Q Btwn <. R , p >. \/ R Btwn <. p , Q >. ) ) <-> ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) ) ) | 
						
							| 47 | 46 | rexbidv |  |-  ( p = P -> ( E. n e. NN ( ( p e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( p Btwn <. Q , R >. \/ Q Btwn <. R , p >. \/ R Btwn <. p , Q >. ) ) <-> E. n e. NN ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) ) ) | 
						
							| 48 | 27 37 47 | eloprabg |  |-  ( ( Q e. V /\ R e. W /\ P e. _V ) -> ( <. <. Q , R >. , P >. e. { <. <. q , r >. , p >. | E. n e. NN ( ( p e. ( EE ` n ) /\ q e. ( EE ` n ) /\ r e. ( EE ` n ) ) /\ ( p Btwn <. q , r >. \/ q Btwn <. r , p >. \/ r Btwn <. p , q >. ) ) } <-> E. n e. NN ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) ) ) | 
						
							| 49 | 17 48 | bitrd |  |-  ( ( Q e. V /\ R e. W /\ P e. _V ) -> ( P Colinear <. Q , R >. <-> E. n e. NN ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) ) ) | 
						
							| 50 | 49 | 3expia |  |-  ( ( Q e. V /\ R e. W ) -> ( P e. _V -> ( P Colinear <. Q , R >. <-> E. n e. NN ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) ) ) ) | 
						
							| 51 | 3 8 50 | pm5.21ndd |  |-  ( ( Q e. V /\ R e. W ) -> ( P Colinear <. Q , R >. <-> E. n e. NN ( ( P e. ( EE ` n ) /\ Q e. ( EE ` n ) /\ R e. ( EE ` n ) ) /\ ( P Btwn <. Q , R >. \/ Q Btwn <. R , P >. \/ R Btwn <. P , Q >. ) ) ) ) |